2641 lines
123 KiB
PHP
2641 lines
123 KiB
PHP
<?php
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/**
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* @file
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* Documentation landing page and topics, plus core library hooks.
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*/
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/**
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* @mainpage
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* Welcome to the Drupal API Documentation!
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*
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* This site is an API reference for Drupal, generated from comments embedded
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* in the source code. More in-depth documentation can be found at
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* https://www.drupal.org/developing/api.
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*
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* Here are some topics to help you get started developing with Drupal.
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*
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* @section essentials Essential background concepts
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*
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* - @link oo_conventions Object-oriented conventions used in Drupal @endlink
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* - @link extending Extending and altering Drupal @endlink
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* - @link best_practices Security and best practices @endlink
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* - @link info_types Types of information in Drupal @endlink
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*
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* @section interface User interface
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*
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* - @link menu Menu entries, local tasks, and other links @endlink
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* - @link routing Routing API and page controllers @endlink
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* - @link form_api Forms @endlink
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* - @link block_api Blocks @endlink
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* - @link ajax Ajax @endlink
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*
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* @section store_retrieve Storing and retrieving data
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*
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* - @link entity_api Entities @endlink
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* - @link field Fields @endlink
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* - @link config_api Configuration API @endlink
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* - @link state_api State API @endlink
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* - @link views_overview Views @endlink
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* - @link database Database abstraction layer @endlink
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*
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* @section other_essentials Other essential APIs
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*
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* - @link plugin_api Plugins @endlink
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* - @link container Services and the Dependency Injection Container @endlink
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* - @link events Events @endlink
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* - @link i18n Internationalization @endlink
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* - @link cache Caching @endlink
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* - @link utility Utility classes and functions @endlink
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* - @link user_api User accounts, permissions, and roles @endlink
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* - @link theme_render Render API @endlink
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* - @link themeable Theme system @endlink
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* - @link update_api Update API @endlink
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* - @link migration Migration @endlink
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*
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* @section additional Additional topics
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*
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* - @link batch Batch API @endlink
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* - @link queue Queue API @endlink
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* - @link typed_data Typed Data @endlink
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* - @link testing Automated tests @endlink
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* - @link php_assert PHP Runtime Assert Statements @endlink
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* - @link third_party Integrating third-party applications @endlink
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*
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* @section more_info Further information
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*
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* - @link https://www.drupal.org/project/examples Examples project (sample modules) @endlink
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* - @link https://www.drupal.org/list-changes API change notices @endlink
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* - @link https://www.drupal.org/docs/drupal-apis Drupal API longer references @endlink
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*/
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/**
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* @defgroup third_party REST and Application Integration
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* @{
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* Integrating third-party applications using REST and related operations.
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*
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* @section sec_overview Overview of web services
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* Web services make it possible for applications and websites to read and
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* update information from other websites. There are several standard
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* techniques for providing web services, including:
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* - SOAP: http://wikipedia.org/wiki/SOAP
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* - XML-RPC: http://wikipedia.org/wiki/XML-RPC
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* - REST: http://wikipedia.org/wiki/Representational_state_transfer
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* Drupal sites can both provide web services and integrate third-party web
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* services.
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*
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* @section sec_rest_overview Overview of REST
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* The REST technique uses basic HTTP requests to obtain and update data, where
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* each web service defines a specific API (HTTP GET and/or POST parameters and
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* returned response) for its HTTP requests. REST requests are separated into
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* several types, known as methods, including:
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* - GET: Requests to obtain data.
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* - POST: Requests to update or create data.
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* - PUT: Requests to update or create data (limited support, currently unused
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* by entity resources).
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* - PATCH: Requests to update a subset of data, such as one field.
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* - DELETE: Requests to delete data.
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* The Drupal Core REST module provides support for GET, POST, PATCH, and DELETE
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* quests on entities, GET requests on the database log from the Database
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* Logging module, and a plugin framework for providing REST support for other
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* data and other methods.
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*
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* REST requests can be authenticated. The Drupal Core Basic Auth module
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* provides authentication using the HTTP Basic protocol; the contributed module
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* OAuth (https://www.drupal.org/project/oauth) implements the OAuth
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* authentication protocol. You can also use cookie-based authentication, which
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* would require users to be logged into the Drupal site while using the
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* application on the third-party site that is using the REST service.
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*
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* @section sec_rest Enabling REST for entities and the log
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* Here are the steps to take to use the REST operations provided by Drupal
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* Core:
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* - Enable the REST module, plus Basic Auth (or another authentication method)
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* and HAL.
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* - Node entity support is configured by default. If you would like to support
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* other types of entities, you can copy
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* core/modules/hal/config/optional/rest.resource.entity.node.yml to your sync
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* configuration directory, appropriately modified for other entity types,
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* and import it. Support for GET on the log from the Database Logging module
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* can also be enabled in this way; in this case, the 'entity:node' line
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* in the configuration would be replaced by the appropriate plugin ID,
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* 'dblog'.
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* - Set up permissions to allow the desired REST operations for a role, and set
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* up one or more user accounts to perform the operations.
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* - To perform a REST operation, send a request to either the canonical URL
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* for an entity (such as node/12345 for a node), or if the entity does not
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* have a canonical URL, a URL like entity/(type)/(ID). The URL for a log
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* entry is dblog/(ID). The request must have the following properties:
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* - The request method must be set to the REST method you are using (POST,
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* GET, PATCH, etc.).
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* - The content type for the data you send, or the accept type for the
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* data you are receiving, must be set to 'application/hal+json'.
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* - If you are sending data, it must be JSON-encoded.
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* - You'll also need to make sure the authentication information is sent
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* with the request, unless you have allowed access to anonymous users.
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*
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* For more detailed information on setting up REST, see
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* https://www.drupal.org/documentation/modules/rest.
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*
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* @section sec_plugins Defining new REST plugins
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* The REST framework in the REST module has support built in for entities, but
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* it is also an extensible plugin-based system. REST plugins implement
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* interface \Drupal\rest\Plugin\ResourceInterface, and generally extend base
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* class \Drupal\rest\Plugin\ResourceBase. They are annotated with
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* \Drupal\rest\Annotation\RestResource annotation, and must be in plugin
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* namespace subdirectory Plugin\rest\resource. For more information on how to
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* create plugins, see the @link plugin_api Plugin API topic. @endlink
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*
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* If you create a new REST plugin, you will also need to enable it by
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* providing default configuration or configuration import, as outlined in
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* @ref sec_rest above.
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*
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* @section sec_integrate Integrating data from other sites into Drupal
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* If you want to integrate data from other websites into Drupal, here are
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* some notes:
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* - There are contributed modules available for integrating many third-party
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* sites into Drupal. Search on https://www.drupal.org/project/project_module
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* - If there is not an existing module, you will need to find documentation on
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* the specific web services API for the site you are trying to integrate.
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* - There are several classes and functions that are useful for interacting
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* with web services:
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* - You should make requests using the 'http_client' service, which
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* implements \GuzzleHttp\ClientInterface. See the
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* @link container Services topic @endlink for more information on
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* services. If you cannot use dependency injection to retrieve this
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* service, the \Drupal::httpClient() method is available. A good example
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* of how to use this service can be found in
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* \Drupal\aggregator\Plugin\aggregator\fetcher\DefaultFetcher
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* - \Drupal\Component\Serialization\Json (JSON encoding and decoding).
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* - PHP has functions and classes for parsing XML; see
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* http://php.net/manual/refs.xml.php
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* @}
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*/
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/**
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* @defgroup state_api State API
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* @{
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* Information about the State API.
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*
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* The State API is one of several methods in Drupal for storing information.
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* See the @link info_types Information types topic @endlink for an
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* overview of the different types of information.
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*
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* The basic entry point into the State API is \Drupal::state(), which returns
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* an object of class \Drupal\Core\State\StateInterface. This class has
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* methods for storing and retrieving state information; each piece of state
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* information is associated with a string-valued key. Example:
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* @code
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* // Get the state class.
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* $state = \Drupal::state();
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* // Find out when cron was last run; the key is 'system.cron_last'.
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* $time = $state->get('system.cron_last');
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* // Set the cron run time to the current request time.
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* $state->set('system.cron_last', \Drupal::time()->getRequestTime());
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* @endcode
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*
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* For more on the State API, see https://www.drupal.org/developing/api/8/state
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* @}
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*/
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/**
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* @defgroup config_api Configuration API
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* @{
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* Information about the Configuration API.
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*
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* The Configuration API is one of several methods in Drupal for storing
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* information. See the @link info_types Information types topic @endlink for
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* an overview of the different types of information. The sections below have
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* more information about the configuration API; see
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* https://www.drupal.org/docs/drupal-apis/configuration-api for more details.
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*
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* @section sec_storage Configuration storage
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* In Drupal, there is a concept of the "active" configuration, which is the
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* configuration that is currently in use for a site. The storage used for the
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* active configuration is configurable: it could be in the database, in files
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* in a particular directory, or in other storage backends; the default storage
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* is in the database. Module developers must use the configuration API to
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* access the active configuration, rather than being concerned about the
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* details of where and how it is stored.
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*
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* Configuration is divided into individual objects, each of which has a
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* unique name or key. Some modules will have only one configuration object,
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* typically called 'mymodule.settings'; some modules will have many. Within
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* a configuration object, configuration settings have data types (integer,
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* string, Boolean, etc.) and settings can also exist in a nested hierarchy,
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* known as a "mapping".
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*
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* Configuration can also be overridden on a global, per-language, or
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* per-module basis. See https://www.drupal.org/node/1928898 for more
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* information.
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*
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* @section sec_yaml Configuration YAML files
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* Whether or not configuration files are being used for the active
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* configuration storage on a particular site, configuration files are always
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* used for:
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* - Defining the default configuration for an extension (module, theme, or
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* profile), which is imported to the active storage when the extension is
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* enabled. These configuration items are located in the config/install
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* sub-directory of the extension. Note that changes to this configuration
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* after a module or theme is already enabled have no effect; to make a
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* configuration change after a module or theme is enabled, you would need to
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* uninstall/reinstall or use a hook_update_N() function.
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* - Defining optional configuration for a module or theme. Optional
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* configuration items are located in the config/optional sub-directory of the
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* extension. These configuration items have dependencies that are not
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* explicit dependencies of the extension, so they are only installed if all
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* dependencies are met. For example, in the scenario that module A defines a
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* dependency which requires module B, but module A is installed first and
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* module B some time later, then module A's config/optional directory will be
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* scanned at that time for newly met dependencies, and the configuration will
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* be installed then. If module B is never installed, the configuration item
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* will not be installed either.
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* - Exporting and importing configuration.
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*
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* The file storage format for configuration information in Drupal is
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* @link http://wikipedia.org/wiki/YAML YAML files. @endlink Configuration is
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* divided into files, each containing one configuration object. The file name
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* for a configuration object is equal to the unique name of the configuration,
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* with a '.yml' extension. The default configuration files for each module are
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* placed in the config/install directory under the top-level module directory,
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* so look there in most Core modules for examples.
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*
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* @section sec_schema Configuration schema and translation
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* Each configuration file has a specific structure, which is expressed as a
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* YAML-based configuration schema. The configuration schema details the
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* structure of the configuration, its data types, and which of its values need
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* to be translatable. Each module needs to define its configuration schema in
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* files in the config/schema directory under the top-level module directory, so
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* look there in most Core modules for examples.
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*
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* Configuration can be internationalized; see the
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* @link i18n Internationalization topic @endlink for more information. Data
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* types label, text, and date_format in configuration schema are translatable;
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* string is non-translatable text (the 'translatable' property on a schema
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* data type definition indicates that it is translatable).
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*
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* @section sec_simple Simple configuration
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* The simple configuration API should be used for information that will always
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* have exactly one copy or version. For instance, if your module has a
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* setting that is either on or off, then this is only defined once, and it
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* would be a Boolean-valued simple configuration setting.
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*
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* The first task in using the simple configuration API is to define the
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* configuration file structure, file name, and schema of your settings (see
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* @ref sec_yaml above). Once you have done that, you can retrieve the active
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* configuration object that corresponds to configuration file mymodule.foo.yml
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* with a call to:
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* @code
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* $config = \Drupal::config('mymodule.foo');
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* @endcode
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*
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* This will be an object of class \Drupal\Core\Config\Config, which has methods
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* for getting configuration information. For instance, if your YAML file
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* structure looks like this:
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* @code
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* enabled: '0'
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* bar:
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* baz: 'string1'
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* boo: 34
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* @endcode
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* you can make calls such as:
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* @code
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* // Get a single value.
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* $enabled = $config->get('enabled');
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* // Get an associative array.
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* $bar = $config->get('bar');
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* // Get one element of the array.
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* $bar_baz = $config->get('bar.baz');
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* @endcode
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*
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* The Config object that was obtained and used in the previous examples does
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* not allow you to change configuration. If you want to change configuration,
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* you will instead need to get the Config object by making a call to
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* getEditable() on the config factory:
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* @code
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* $config =\Drupal::service('config.factory')->getEditable('mymodule.foo');
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* @endcode
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*
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* Individual configuration values can be changed or added using the set()
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* method and saved using the save() method:
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* @code
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* // Set a scalar value.
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* $config->set('enabled', 1);
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* // Save the configuration.
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* $config->save();
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* @endcode
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*
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* Configuration values can also be unset using the clear() method, which is
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* also chainable:
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* @code
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* $config->clear('bar.boo')->save();
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* $config_data = $config->get('bar');
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* @endcode
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* In this example $config_data would return an array with one key - 'baz' -
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* because 'boo' was unset.
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*
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* @section sec_entity Configuration entities
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* In contrast to the simple configuration settings described in the previous
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* section, if your module allows users to create zero or more items (where
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* "items" are things like content type definitions, view definitions, and the
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* like), then you need to define a configuration entity type to store your
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* configuration. Creating an entity type, loading entities, and querying them
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* are outlined in the @link entity_api Entity API topic. @endlink Here are a
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* few additional steps and notes specific to configuration entities:
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* - For examples, look for classes that implement
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* \Drupal\Core\Config\Entity\ConfigEntityInterface -- one good example is
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* the \Drupal\user\Entity\Role entity type.
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* - In the entity type annotation, you will need to define a 'config_prefix'
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* string. When Drupal stores a configuration item, it will be given a name
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* composed of your module name, your chosen config prefix, and the ID of
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* the individual item, separated by '.'. For example, in the Role entity,
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* the config prefix is 'role', so one configuration item might be named
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* user.role.anonymous, with configuration file user.role.anonymous.yml.
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* - You will need to define the schema for your configuration in your
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* modulename.schema.yml file, with an entry for 'modulename.config_prefix.*'.
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* For example, for the Role entity, the file user.schema.yml has an entry
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* user.role.*; see @ref sec_yaml above for more information.
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* - Your module can provide default/optional configuration entities in YAML
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* files; see @ref sec_yaml above for more information.
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* - Some configuration entities have dependencies on other configuration
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* entities, and module developers need to consider this so that configuration
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* can be imported, uninstalled, and synchronized in the right order. For
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* example, a field display configuration entity would need to depend on
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* field configuration, which depends on field and bundle configuration.
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* Configuration entity classes expose dependencies by overriding the
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* \Drupal\Core\Config\Entity\ConfigEntityInterface::calculateDependencies()
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* method.
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* - On routes for paths starting with '/admin' or otherwise designated as
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* administration paths (such as node editing when it is set as an admin
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* operation), if they have configuration entity placeholders, configuration
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* entities are normally loaded in their original language, without
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* translations or other overrides. This is usually desirable, because most
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* admin paths are for editing configuration, and you need that to be in the
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* source language and to lack possibly dynamic overrides. If for some reason
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* you need to have your configuration entity loaded in the currently-selected
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* language on an admin path (for instance, if you go to
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* example.com/es/admin/your_path and you need the entity to be in Spanish),
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* then you can add a 'with_config_overrides' parameter option to your route.
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* The same applies if you need to load the entity with overrides (or
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* translated) on an admin path like '/node/add/article' (when configured to
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* be an admin path). Here's an example using the configurable_language config
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* entity:
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* @code
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* my_module.my_route:
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* path: '/admin/my-path/{configurable_language}'
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* defaults:
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* _controller: '\Drupal\my_module\MyController::myMethod'
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* options:
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* parameters:
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* configurable_language:
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* type: entity:configurable_language
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* with_config_overrides: TRUE
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* @endcode
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* With the route defined this way, the $configurable_language parameter to
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* your controller method will come in translated to the current language.
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* Without the parameter options section, it would be in the original
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* language, untranslated.
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*
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* @see i18n
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*
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* @}
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*/
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/**
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* @defgroup cache Cache API
|
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* @{
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* Information about the Drupal Cache API
|
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*
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* @section basics Basics
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*
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* Note: If not specified, all of the methods mentioned here belong to
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* \Drupal\Core\Cache\CacheBackendInterface.
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*
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* The Cache API is used to store data that takes a long time to compute.
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* Caching can either be permanent or valid only for a certain time span, and
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* the cache can contain any type of data.
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*
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* To use the Cache API:
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* - Request a cache object through \Drupal::cache() or by injecting a cache
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* service.
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* - Define a Cache ID (cid) value for your data. A cid is a string, which must
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* contain enough information to uniquely identify the data. For example, if
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* your data contains translated strings, then your cid value must include the
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* interface text language selected for page.
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* - Call the get() method to attempt a cache read, to see if the cache already
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* contains your data.
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* - If your data is not already in the cache, compute it and add it to the
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* cache using the set() method. The third argument of set() can be used to
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* control the lifetime of your cache item.
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*
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* Example:
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* @code
|
|
* $cid = 'mymodule_example:' . \Drupal::languageManager()->getCurrentLanguage()->getId();
|
|
*
|
|
* $data = NULL;
|
|
* if ($cache = \Drupal::cache()->get($cid)) {
|
|
* $data = $cache->data;
|
|
* }
|
|
* else {
|
|
* $data = my_module_complicated_calculation();
|
|
* \Drupal::cache()->set($cid, $data);
|
|
* }
|
|
* @endcode
|
|
*
|
|
* Note the use of $data and $cache->data in the above example. Calls to
|
|
* \Drupal::cache()->get() return a record that contains the information stored
|
|
* by \Drupal::cache()->set() in the data property as well as additional meta
|
|
* information about the cached data. In order to make use of the cached data
|
|
* you can access it via $cache->data.
|
|
*
|
|
* @section bins Cache bins
|
|
*
|
|
* Cache storage is separated into "bins", each containing various cache items.
|
|
* Each bin can be configured separately; see @ref configuration.
|
|
*
|
|
* When you request a cache object, you can specify the bin name in your call to
|
|
* \Drupal::cache(). Alternatively, you can request a bin by getting service
|
|
* "cache.nameofbin" from the container. The default bin is called "default", with
|
|
* service name "cache.default", it is used to store common and frequently used
|
|
* caches.
|
|
*
|
|
* Other common cache bins are the following:
|
|
* - bootstrap: Data needed from the beginning to the end of most requests,
|
|
* that has a very strict limit on variations and is invalidated rarely.
|
|
* - render: Contains cached HTML strings like cached pages and blocks, can
|
|
* grow to large size.
|
|
* - data: Contains data that can vary by path or similar context.
|
|
* - discovery: Contains cached discovery data for things such as plugins,
|
|
* views_data, or YAML discovered data such as library info.
|
|
*
|
|
* A module can define a cache bin by defining a service in its
|
|
* modulename.services.yml file as follows (substituting the desired name for
|
|
* "nameofbin"):
|
|
* @code
|
|
* cache.nameofbin:
|
|
* class: Drupal\Core\Cache\CacheBackendInterface
|
|
* tags:
|
|
* - { name: cache.bin }
|
|
* factory: ['@cache_factory', 'get']
|
|
* arguments: [nameofbin]
|
|
* @endcode
|
|
* See the @link container Services topic @endlink for more on defining
|
|
* services.
|
|
*
|
|
* @section delete Deletion
|
|
*
|
|
* There are two ways to remove an item from the cache:
|
|
* - Deletion (using delete(), deleteMultiple() or deleteAll()) permanently
|
|
* removes the item from the cache.
|
|
* - Invalidation (using invalidate(), invalidateMultiple() or invalidateAll())
|
|
* is a "soft" delete that only marks items as "invalid", meaning "not fresh"
|
|
* or "not fresh enough". Invalid items are not usually returned from the
|
|
* cache, so in most ways they behave as if they have been deleted. However,
|
|
* it is possible to retrieve invalid items, if they have not yet been
|
|
* permanently removed by the garbage collector, by passing TRUE as the second
|
|
* argument for get($cid, $allow_invalid).
|
|
*
|
|
* Use deletion if a cache item is no longer useful; for instance, if the item
|
|
* contains references to data that has been deleted. Use invalidation if the
|
|
* cached item may still be useful to some callers until it has been updated
|
|
* with fresh data. The fact that it was fresh a short while ago may often be
|
|
* sufficient.
|
|
*
|
|
* Invalidation is particularly useful to protect against stampedes. Rather than
|
|
* having multiple concurrent requests updating the same cache item when it
|
|
* expires or is deleted, there can be one request updating the cache, while the
|
|
* other requests can proceed using the stale value. As soon as the cache item
|
|
* has been updated, all future requests will use the updated value.
|
|
*
|
|
* @section tags Cache Tags
|
|
*
|
|
* The fourth argument of the set() method can be used to specify cache tags,
|
|
* which are used to identify which data is included in each cache item. A cache
|
|
* item can have multiple cache tags (an array of cache tags), and each cache
|
|
* tag is a string. The convention is to generate cache tags of the form
|
|
* [prefix]:[suffix]. Usually, you'll want to associate the cache tags of
|
|
* entities, or entity listings. You won't have to manually construct cache tags
|
|
* for them — just get their cache tags via
|
|
* \Drupal\Core\Cache\CacheableDependencyInterface::getCacheTags() and
|
|
* \Drupal\Core\Entity\EntityTypeInterface::getListCacheTags().
|
|
* Data that has been tagged can be invalidated as a group: no matter the Cache
|
|
* ID (cid) of the cache item, no matter in which cache bin a cache item lives;
|
|
* as long as it is tagged with a certain cache tag, it will be invalidated.
|
|
*
|
|
* Because of that, cache tags are a solution to the cache invalidation problem:
|
|
* - For caching to be effective, each cache item must only be invalidated when
|
|
* absolutely necessary. (i.e. maximizing the cache hit ratio.)
|
|
* - For caching to be correct, each cache item that depends on a certain thing
|
|
* must be invalidated whenever that certain thing is modified.
|
|
*
|
|
* A typical scenario: a user has modified a node that appears in two views,
|
|
* three blocks and on twelve pages. Without cache tags, we couldn't possibly
|
|
* know which cache items to invalidate, so we'd have to invalidate everything:
|
|
* we had to sacrifice effectiveness to achieve correctness. With cache tags, we
|
|
* can have both.
|
|
*
|
|
* Example:
|
|
* @code
|
|
* // A cache item with nodes, users, and some custom module data.
|
|
* $tags = array(
|
|
* 'my_custom_tag',
|
|
* 'node:1',
|
|
* 'node:3',
|
|
* 'user:7',
|
|
* );
|
|
* \Drupal::cache()->set($cid, $data, CacheBackendInterface::CACHE_PERMANENT, $tags);
|
|
*
|
|
* // Invalidate all cache items with certain tags.
|
|
* \Drupal\Core\Cache\Cache::invalidateTags(array('user:1'));
|
|
* @endcode
|
|
*
|
|
* Drupal is a content management system, so naturally you want changes to your
|
|
* content to be reflected everywhere, immediately. That's why we made sure that
|
|
* every entity type in Drupal 8 automatically has support for cache tags: when
|
|
* you save an entity, you can be sure that the cache items that have the
|
|
* corresponding cache tags will be invalidated.
|
|
* This also is the case when you define your own entity types: you'll get the
|
|
* exact same cache tag invalidation as any of the built-in entity types, with
|
|
* the ability to override any of the default behavior if needed.
|
|
* See \Drupal\Core\Cache\CacheableDependencyInterface::getCacheTags(),
|
|
* \Drupal\Core\Entity\EntityTypeInterface::getListCacheTags(),
|
|
* \Drupal\Core\Entity\Entity::invalidateTagsOnSave() and
|
|
* \Drupal\Core\Entity\Entity::invalidateTagsOnDelete().
|
|
*
|
|
* @section context Cache contexts
|
|
*
|
|
* Some computed data depends on contextual data, such as the user roles of the
|
|
* logged-in user who is viewing a page, the language the page is being rendered
|
|
* in, the theme being used, etc. When caching the output of such a calculation,
|
|
* you must cache each variation separately, along with information about which
|
|
* variation of the contextual data was used in the calculation. The next time
|
|
* the computed data is needed, if the context matches that for an existing
|
|
* cached data set, the cached data can be reused; if no context matches, a new
|
|
* data set can be calculated and cached for later use.
|
|
*
|
|
* Cache contexts are services tagged with 'cache.context', whose classes
|
|
* implement \Drupal\Core\Cache\Context\CacheContextInterface. See
|
|
* https://www.drupal.org/docs/drupal-apis/cache-api/cache-contexts for more
|
|
* information on cache contexts, including a list of the contexts that exist in
|
|
* Drupal core, and information on how to define your own contexts. See the
|
|
* @link container Services and the Dependency Injection Container @endlink
|
|
* topic for more information about services.
|
|
*
|
|
* Typically, the cache context is specified as part of the #cache property
|
|
* of a render array; see the Caching section of the
|
|
* @link theme_render Render API overview topic @endlink for details.
|
|
*
|
|
* @section configuration Configuration
|
|
*
|
|
* By default cached data is stored in the database. This can be configured
|
|
* though so that all cached data, or that of an individual cache bin, uses a
|
|
* different cache backend, such as APCu or Memcache, for storage.
|
|
*
|
|
* In a settings.php file, you can override the service used for a particular
|
|
* cache bin. For example, if your service implementation of
|
|
* \Drupal\Core\Cache\CacheBackendInterface was called cache.custom, the
|
|
* following line would make Drupal use it for the 'cache_render' bin:
|
|
* @code
|
|
* $settings['cache']['bins']['render'] = 'cache.custom';
|
|
* @endcode
|
|
*
|
|
* Additionally, you can register your cache implementation to be used by
|
|
* default for all cache bins with:
|
|
* @code
|
|
* $settings['cache']['default'] = 'cache.custom';
|
|
* @endcode
|
|
*
|
|
* For cache bins that are stored in the database, the number of rows is limited
|
|
* to 5000 by default. This can be changed for all database cache bins. For
|
|
* example, to instead limit the number of rows to 50000:
|
|
* @code
|
|
* $settings['database_cache_max_rows']['default'] = 50000;
|
|
* @endcode
|
|
*
|
|
* Or per bin (in this example we allow infinite entries):
|
|
* @code
|
|
* $settings['database_cache_max_rows']['bins']['dynamic_page_cache'] = -1;
|
|
* @endcode
|
|
*
|
|
* For monitoring reasons it might be useful to figure out the amount of data
|
|
* stored in tables. The following SQL snippet can be used for that:
|
|
* @code
|
|
* SELECT table_name AS `Table`, table_rows AS 'Num. of Rows',
|
|
* ROUND(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` FROM
|
|
* information_schema.TABLES WHERE table_schema = '***DATABASE_NAME***' AND
|
|
* table_name LIKE 'cache_%' ORDER BY (data_length + index_length) DESC
|
|
* LIMIT 10;
|
|
* @endcode
|
|
*
|
|
* @see \Drupal\Core\Cache\DatabaseBackend
|
|
*
|
|
* Finally, you can chain multiple cache backends together, see
|
|
* \Drupal\Core\Cache\ChainedFastBackend and \Drupal\Core\Cache\BackendChain.
|
|
*
|
|
* @see https://www.drupal.org/node/1884796
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup user_api User accounts, permissions, and roles
|
|
* @{
|
|
* API for user accounts, access checking, roles, and permissions.
|
|
*
|
|
* @section sec_overview Overview and terminology
|
|
* Drupal's permission system is based on the concepts of accounts, roles,
|
|
* and permissions.
|
|
*
|
|
* Users (site visitors) have accounts, which include a user name, an email
|
|
* address, a password (or some other means of authentication), and possibly
|
|
* other fields (if defined on the site). Anonymous users have an implicit
|
|
* account that does not have a real user name or any account information.
|
|
*
|
|
* Each user account is assigned one or more roles. The anonymous user account
|
|
* automatically has the anonymous user role; real user accounts
|
|
* automatically have the authenticated user role, plus any roles defined on
|
|
* the site that they have been assigned.
|
|
*
|
|
* Each role, including the special anonymous and authenticated user roles, is
|
|
* granted one or more named permissions, which allow them to perform certain
|
|
* tasks or view certain content on the site. It is possible to designate a
|
|
* role to be the "administrator" role; if this is set up, this role is
|
|
* automatically granted all available permissions whenever a module is
|
|
* enabled that defines permissions.
|
|
*
|
|
* All code in Drupal that allows users to perform tasks or view content must
|
|
* check that the current user has the correct permission before allowing the
|
|
* action. In the standard case, access checking consists of answering the
|
|
* question "Does the current user have permission 'foo'?", and allowing or
|
|
* denying access based on the answer. Note that access checking should nearly
|
|
* always be done at the permission level, not by checking for a particular role
|
|
* or user ID, so that site administrators can set up user accounts and roles
|
|
* appropriately for their particular sites.
|
|
*
|
|
* @section sec_define Defining permissions
|
|
* Modules define permissions via a $module.permissions.yml file. See
|
|
* \Drupal\user\PermissionHandler for documentation of permissions.yml files.
|
|
*
|
|
* @section sec_access Access permission checking
|
|
* Depending on the situation, there are several methods for ensuring that
|
|
* access checks are done properly in Drupal:
|
|
* - Routes: When you register a route, include a 'requirements' section that
|
|
* either gives the machine name of the permission that is needed to visit the
|
|
* URL of the route, or tells Drupal to use an access check method or service
|
|
* to check access. See the @link menu Routing topic @endlink for more
|
|
* information.
|
|
* - Entities: Access for various entity operations is designated either with
|
|
* simple permissions or access control handler classes in the entity
|
|
* annotation. See the @link entity_api Entity API topic @endlink for more
|
|
* information.
|
|
* - Other code: There is a 'current_user' service, which can be injected into
|
|
* classes to provide access to the current user account (see the
|
|
* @link container Services and Dependency Injection topic @endlink for more
|
|
* information on dependency injection). In code that cannot use dependency
|
|
* injection, you can access this service and retrieve the current user
|
|
* account object by calling \Drupal::currentUser(). Once you have a user
|
|
* object for the current user (implementing \Drupal\user\UserInterface), you
|
|
* can call inherited method
|
|
* \Drupal\Core\Session\AccountInterface::hasPermission() to check
|
|
* permissions, or pass this object into other functions/methods.
|
|
* - Forms: Each element of a form array can have a Boolean '#access' property,
|
|
* which determines whether that element is visible and/or usable. This is a
|
|
* common need in forms, so the current user service (described above) is
|
|
* injected into the form base class as method
|
|
* \Drupal\Core\Form\FormBase::currentUser().
|
|
*
|
|
* @section sec_entities User and role objects
|
|
* User objects in Drupal are entity items, implementing
|
|
* \Drupal\user\UserInterface. Role objects in Drupal are also entity items,
|
|
* implementing \Drupal\user\RoleInterface. See the
|
|
* @link entity_api Entity API topic @endlink for more information about
|
|
* entities in general (including how to load, create, modify, and query them).
|
|
*
|
|
* Roles often need to be manipulated in automated test code, such as to add
|
|
* permissions to them. Here's an example:
|
|
* @code
|
|
* $role = \Drupal\user\Entity\Role::load('authenticated');
|
|
* $role->grantPermission('access comments');
|
|
* $role->save();
|
|
* @endcode
|
|
*
|
|
* Other important interfaces:
|
|
* - \Drupal\Core\Session\AccountInterface: The part of UserInterface that
|
|
* deals with access checking. In writing code that checks access, your
|
|
* method parameters should use this interface, not UserInterface.
|
|
* - \Drupal\Core\Session\AccountProxyInterface: The interface for the
|
|
* current_user service (described above).
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup container Services and Dependency Injection Container
|
|
* @{
|
|
* Overview of the Dependency Injection Container and Services.
|
|
*
|
|
* @section sec_overview Overview of container, injection, and services
|
|
* The Services and Dependency Injection Container concepts have been adopted by
|
|
* Drupal from the
|
|
* @link http://symfony.com/doc/current/components/dependency_injection.html
|
|
* Symfony DependencyInjection component. @endlink A "service" (such as
|
|
* accessing the database, sending email, or translating user interface text) is
|
|
* defined (given a name and an interface or at least a class that defines the
|
|
* methods that may be called), and a default class is designated to provide the
|
|
* service. These two steps must be done together, and can be done by Drupal
|
|
* Core or a module. Other modules can then define alternative classes to
|
|
* provide the same services, overriding the default classes. Classes and
|
|
* functions that need to use the service should always instantiate the class
|
|
* via the dependency injection container (also known simply as the
|
|
* "container"), rather than instantiating a particular service provider class
|
|
* directly, so that they get the correct class (default or overridden).
|
|
*
|
|
* See https://www.drupal.org/node/2133171 for more detailed information on
|
|
* services and the dependency injection container.
|
|
*
|
|
* @section sec_discover Discovering existing services
|
|
* Drupal core defines many core services in the core.services.yml file (in the
|
|
* top-level core directory). Some Drupal Core modules and contributed modules
|
|
* also define services in modulename.services.yml files. API reference sites
|
|
* (such as https://api.drupal.org) generate lists of all existing services from
|
|
* these files. Look for the Services link in the API Navigation block.
|
|
* Alternatively you can look through the individual files manually.
|
|
*
|
|
* A typical service definition in a *.services.yml file looks like this:
|
|
* @code
|
|
* path_alias.manager:
|
|
* class: Drupal\path_alias\AliasManager
|
|
* arguments: ['@path_alias.repository', '@path_alias.whitelist', '@language_manager']
|
|
* @endcode
|
|
* Some services use other services as factories; a typical service definition
|
|
* is:
|
|
* @code
|
|
* cache.entity:
|
|
* class: Drupal\Core\Cache\CacheBackendInterface
|
|
* tags:
|
|
* - { name: cache.bin }
|
|
* factory: ['@cache_factory', 'get']
|
|
* arguments: [entity]
|
|
* @endcode
|
|
*
|
|
* The first line of a service definition gives the unique machine name of the
|
|
* service. This is often prefixed by the module name if provided by a module;
|
|
* however, by convention some service names are prefixed by a group name
|
|
* instead, such as cache.* for cache bins and plugin.manager.* for plugin
|
|
* managers.
|
|
*
|
|
* The class line either gives the default class that provides the service, or
|
|
* if the service uses a factory class, the interface for the service. If the
|
|
* class depends on other services, the arguments line lists the machine
|
|
* names of the dependencies (preceded by '@'); objects for each of these
|
|
* services are instantiated from the container and passed to the class
|
|
* constructor when the service class is instantiated. Other arguments can also
|
|
* be passed in; see the section at https://www.drupal.org/node/2133171 for more
|
|
* detailed information.
|
|
*
|
|
* Services using factories can be defined as shown in the above example, if the
|
|
* factory is itself a service. The factory can also be a class; details of how
|
|
* to use service factories can be found in the section at
|
|
* https://www.drupal.org/node/2133171.
|
|
*
|
|
* @section sec_container Accessing a service through the container
|
|
* As noted above, if you need to use a service in your code, you should always
|
|
* instantiate the service class via a call to the container, using the machine
|
|
* name of the service, so that the default class can be overridden. There are
|
|
* several ways to make sure this happens:
|
|
* - For service-providing classes, see other sections of this documentation
|
|
* describing how to pass services as arguments to the constructor.
|
|
* - Plugin classes, controllers, and similar classes have create() or
|
|
* createInstance() methods that are used to create an instance of the class.
|
|
* These methods come from different interfaces, and have different
|
|
* arguments, but they all include an argument $container of type
|
|
* \Symfony\Component\DependencyInjection\ContainerInterface.
|
|
* If you are defining one of these classes, in the create() or
|
|
* createInstance() method, call $container->get('my_service.name') to
|
|
* instantiate a service. The results of these calls are generally passed to
|
|
* the class constructor and saved as member variables in the class.
|
|
* - For functions and class methods that do not have access to either of
|
|
* the above methods of dependency injection, you can use service location to
|
|
* access services, via a call to the global \Drupal class. This class has
|
|
* special methods for accessing commonly-used services, or you can call a
|
|
* generic method to access any service. Examples:
|
|
* @code
|
|
* // Retrieve the entity_type.manager service object (special method exists).
|
|
* $entity_type_manager = \Drupal::entityTypeManager();
|
|
* // Retrieve the service object for machine name 'foo.bar'.
|
|
* $foobar = \Drupal::service('foo.bar');
|
|
* @endcode
|
|
*
|
|
* As a note, you should always use dependency injection (via service arguments
|
|
* or create()/createInstance() methods) if possible to instantiate services,
|
|
* rather than service location (via the \Drupal class), because:
|
|
* - Dependency injection facilitates writing unit tests, since the container
|
|
* argument can be mocked and the create() method can be bypassed by using
|
|
* the class constructor. If you use the \Drupal class, unit tests are much
|
|
* harder to write and your code has more dependencies.
|
|
* - Having the service interfaces on the class constructor and member variables
|
|
* is useful for IDE auto-complete and self-documentation.
|
|
*
|
|
* @section sec_define Defining a service
|
|
* If your module needs to define a new service, here are the steps:
|
|
* - Choose a unique machine name for your service. Typically, this should
|
|
* start with your module name. Example: my_module.my_service.
|
|
* - Create a PHP interface to define what your service does.
|
|
* - Create a default class implementing your interface that provides your
|
|
* service. If your class needs to use existing services (such as database
|
|
* access), be sure to make these services arguments to your class
|
|
* constructor, and save them in member variables. Also, if the needed
|
|
* services are provided by other modules and not Drupal Core, you'll want
|
|
* these modules to be dependencies of your module.
|
|
* - Add an entry to a modulename.services.yml file for the service. See
|
|
* @ref sec_discover above, or existing *.services.yml files in Core, for the
|
|
* syntax; it will start with your machine name, refer to your default class,
|
|
* and list the services that need to be passed into your constructor.
|
|
*
|
|
* Services can also be defined dynamically, as in the
|
|
* \Drupal\Core\CoreServiceProvider class, but this is less common for modules.
|
|
*
|
|
* @section sec_define Service autowiring
|
|
* Instead of specifying arguments explicitly, the container can also autowire
|
|
* a service's arguments from the constructor's type-hints. See
|
|
* @link https://symfony.com/doc/current/service_container/autowiring.html the Symfony documentation on defining services dependencies automatically @endlink
|
|
* for details.
|
|
*
|
|
* @section sec_tags Service tags
|
|
* Some services have tags, which are defined in the service definition. See
|
|
* @link service_tag Service Tags @endlink for usage.
|
|
*
|
|
* @section sec_injection Overriding the default service class
|
|
* Modules can override the default classes used for services. Here are the
|
|
* steps:
|
|
* - Define a class in the top-level namespace for your module
|
|
* (Drupal\my_module), whose name is the camel-case version of your module's
|
|
* machine name followed by "ServiceProvider" (for example, if your module
|
|
* machine name is my_module, the class must be named
|
|
* MyModuleServiceProvider).
|
|
* - The class needs to implement
|
|
* \Drupal\Core\DependencyInjection\ServiceModifierInterface, which is
|
|
* typically done by extending
|
|
* \Drupal\Core\DependencyInjection\ServiceProviderBase.
|
|
* - The class needs to contain one method: alter(). This method does the
|
|
* actual work of telling Drupal to use your class instead of the default.
|
|
* Here's an example:
|
|
* @code
|
|
* public function alter(ContainerBuilder $container) {
|
|
* // Override the language_manager class with a new class.
|
|
* $definition = $container->getDefinition('language_manager');
|
|
* $definition->setClass('Drupal\my_module\MyLanguageManager');
|
|
* }
|
|
* @endcode
|
|
* Note that $container here is an instance of
|
|
* \Drupal\Core\DependencyInjection\ContainerBuilder.
|
|
*
|
|
* @see https://www.drupal.org/node/2133171
|
|
* @see core.services.yml
|
|
* @see \Drupal
|
|
* @see \Symfony\Component\DependencyInjection\ContainerInterface
|
|
* @see plugin_api
|
|
* @see menu
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup listing_page_service Page header for Services page
|
|
* @{
|
|
* Introduction to services
|
|
*
|
|
* A "service" (such as accessing the database, sending email, or translating
|
|
* user interface text) can be defined by a module or Drupal core. Defining a
|
|
* service means giving it a name and designating a default class to provide the
|
|
* service; ideally, there should also be an interface that defines the methods
|
|
* that may be called. Services are collected into the Dependency Injection
|
|
* Container, and can be overridden to use different classes or different
|
|
* instantiation by modules. See the
|
|
* @link container Services and Dependency Injection Container topic @endlink
|
|
* for details.
|
|
*
|
|
* Some services have tags, which are defined in the service definition. Tags
|
|
* are used to define a group of related services, or to specify some aspect of
|
|
* how the service behaves. See the
|
|
* @link service_tag Service Tags topic @endlink for more information.
|
|
*
|
|
* @see container
|
|
* @see service_tag
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup typed_data Typed Data API
|
|
* @{
|
|
* API for describing data based on a set of available data types.
|
|
*
|
|
* PHP has data types, such as int, string, float, array, etc., and it is an
|
|
* object-oriented language that lets you define classes and interfaces.
|
|
* However, in some cases, it is useful to be able to define an abstract
|
|
* type (as in an interface, free of implementation details), that still has
|
|
* properties (which an interface cannot) as well as meta-data. The Typed Data
|
|
* API provides this abstraction.
|
|
*
|
|
* @section sec_overview Overview
|
|
* Each data type in the Typed Data API is a plugin class (annotation class
|
|
* example: \Drupal\Core\TypedData\Annotation\DataType); these plugins are
|
|
* managed by the typed_data_manager service (by default
|
|
* \Drupal\Core\TypedData\TypedDataManager). Each data object encapsulates a
|
|
* single piece of data, provides access to the metadata, and provides
|
|
* validation capability. Also, the typed data plugins have a shorthand
|
|
* for easily accessing data values, described in @ref sec_tree.
|
|
*
|
|
* The metadata of a data object is defined by an object based on a class called
|
|
* the definition class (see \Drupal\Core\TypedData\DataDefinitionInterface).
|
|
* The class used can vary by data type and can be specified in the data type's
|
|
* plugin definition, while the default is set in the $definition_class property
|
|
* of the annotation class. The default class is
|
|
* \Drupal\Core\TypedData\DataDefinition. For data types provided by a plugin
|
|
* deriver, the plugin deriver can set the definition_class property too.
|
|
* The metadata object provides information about the data, such as the data
|
|
* type, whether it is translatable, the names of its properties (for complex
|
|
* types), and who can access it.
|
|
*
|
|
* See https://www.drupal.org/node/1794140 for more information about the Typed
|
|
* Data API.
|
|
*
|
|
* @section sec_varieties Varieties of typed data
|
|
* There are three kinds of typed data: primitive, complex, and list.
|
|
*
|
|
* @subsection sub_primitive Primitive data types
|
|
* Primitive data types wrap PHP data types and also serve as building blocks
|
|
* for complex and list typed data. Each primitive data type has an interface
|
|
* that extends \Drupal\Core\TypedData\PrimitiveInterface, with getValue()
|
|
* and setValue() methods for accessing the data value, and a default plugin
|
|
* implementation. Here's a list:
|
|
* - \Drupal\Core\TypedData\Type\IntegerInterface: Plugin ID integer,
|
|
* corresponds to PHP type int.
|
|
* - \Drupal\Core\TypedData\Type\StringInterface: Plugin ID string,
|
|
* corresponds to PHP type string.
|
|
* - \Drupal\Core\TypedData\Type\FloatInterface: Plugin ID float,
|
|
* corresponds to PHP type float.
|
|
* - \Drupal\Core\TypedData\Type\BooleanInterface: Plugin ID bool,
|
|
* corresponds to PHP type bool.
|
|
* - \Drupal\Core\TypedData\Type\BinaryInterface: Plugin ID binary,
|
|
* corresponds to a PHP file resource.
|
|
* - \Drupal\Core\TypedData\Type\UriInterface: Plugin ID uri.
|
|
*
|
|
* @subsection sec_complex Complex data
|
|
* Complex data types, with interface
|
|
* \Drupal\Core\TypedData\ComplexDataInterface, represent data with named
|
|
* properties; the properties can be accessed with get() and set() methods.
|
|
* The value of each property is itself a typed data object, which can be
|
|
* primitive, complex, or list data.
|
|
*
|
|
* The base type for most complex data is the
|
|
* \Drupal\Core\TypedData\Plugin\DataType\Map class, which represents an
|
|
* associative array. Map provides its own definition class in the annotation,
|
|
* \Drupal\Core\TypedData\MapDataDefinition, and most complex data classes
|
|
* extend this class. The getValue() and setValue() methods on the Map class
|
|
* enforce the data definition and its property structure.
|
|
*
|
|
* The Drupal Field API uses complex typed data for its field items, with
|
|
* definition class \Drupal\Core\Field\TypedData\FieldItemDataDefinition.
|
|
*
|
|
* @section sec_list Lists
|
|
* List data types, with interface \Drupal\Core\TypedData\ListInterface,
|
|
* represent data that is an ordered list of typed data, all of the same type.
|
|
* More precisely, the plugins in the list must have the same base plugin ID;
|
|
* however, some types (for example field items and entities) are provided by
|
|
* plugin derivatives and the sub IDs can be different.
|
|
*
|
|
* @section sec_tree Tree handling
|
|
* Typed data allows you to use shorthand to get data values nested in the
|
|
* implicit tree structure of the data. For example, to get the value from
|
|
* an entity field item, the Entity Field API allows you to call:
|
|
* @code
|
|
* $value = $entity->fieldName->propertyName;
|
|
* @endcode
|
|
* This is really shorthand for:
|
|
* @code
|
|
* $field_item_list = $entity->get('fieldName');
|
|
* $field_item = $field_item_list->get(0);
|
|
* $property = $field_item->get('propertyName');
|
|
* $value = $property->getValue();
|
|
* @endcode
|
|
* Some notes:
|
|
* - $property, $field_item, and $field_item_list are all typed data objects,
|
|
* while $value is a raw PHP value.
|
|
* - You can call $property->getParent() to get $field_item,
|
|
* $field_item->getParent() to get $field_item_list, or
|
|
* $field_item_list->getParent() to get $typed_entity ($entity wrapped in a
|
|
* typed data object). $typed_entity->getParent() is NULL.
|
|
* - For all of these ->getRoot() returns $typed_entity.
|
|
* - The langcode property is on $field_item_list, but you can access it
|
|
* on $property as well, so that all items will report the same langcode.
|
|
* - When the value of $property is changed by calling $property->setValue(),
|
|
* $property->onChange() will fire, which in turn calls the parent object's
|
|
* onChange() method and so on. This allows parent objects to react upon
|
|
* changes of contained properties or list items.
|
|
*
|
|
* @section sec_defining Defining data types
|
|
* To define a new data type:
|
|
* - Create a class that implements one of the Typed Data interfaces.
|
|
* Typically, you will want to extend one of the classes listed in the
|
|
* sections above as a starting point.
|
|
* - Make your class into a DataType plugin. To do that, put it in namespace
|
|
* \Drupal\yourmodule\Plugin\DataType (where "yourmodule" is your module's
|
|
* short name), and add annotation of type
|
|
* \Drupal\Core\TypedData\Annotation\DataType to the documentation header.
|
|
* See the @link plugin_api Plugin API topic @endlink and the
|
|
* @link annotation Annotations topic @endlink for more information.
|
|
*
|
|
* @section sec_using Using data types
|
|
* The data types of the Typed Data API can be used in several ways, once they
|
|
* have been defined:
|
|
* - In the Field API, data types can be used as the class in the property
|
|
* definition of the field. See the @link field Field API topic @endlink for
|
|
* more information.
|
|
* - In configuration schema files, you can use the unique ID ('id' annotation)
|
|
* from any DataType plugin class as the 'type' value for an entry. See the
|
|
* @link config_api Configuration API topic @endlink for more information.
|
|
* - If you need to create a typed data object in code, first get the
|
|
* typed_data_manager service from the container or by calling
|
|
* \Drupal::typedDataManager(). Then pass the plugin ID to
|
|
* $manager::createDataDefinition() to create an appropriate data definition
|
|
* object. Then pass the data definition object and the value of the data to
|
|
* $manager::create() to create a typed data object.
|
|
*
|
|
* @see plugin_api
|
|
* @see container
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup testing Automated tests
|
|
* @{
|
|
* Overview of PHPUnit and Nightwatch automated tests.
|
|
*
|
|
* The Drupal project has embraced a philosophy of using automated tests,
|
|
* consisting of both unit tests (which test the functionality of classes at a
|
|
* low level) and functional tests (which test the functionality of Drupal
|
|
* systems at a higher level, usually involving web output). The goal is to
|
|
* have test coverage for all or most of the components and features, and to
|
|
* run the automated tests before any code is changed or added, to make sure
|
|
* it doesn't break any existing functionality (regression testing).
|
|
*
|
|
* In order to implement this philosophy, developers need to do the following:
|
|
* - When making a patch to fix a bug, make sure that the bug fix patch includes
|
|
* a test that fails without the code change and passes with the code change.
|
|
* This helps reviewers understand what the bug is, demonstrates that the code
|
|
* actually fixes the bug, and ensures the bug will not reappear due to later
|
|
* code changes.
|
|
* - When making a patch to implement a new feature, include new unit and/or
|
|
* functional tests in the patch. This serves to both demonstrate that the
|
|
* code actually works, and ensure that later changes do not break the new
|
|
* functionality.
|
|
*
|
|
* @section write_test Writing tests
|
|
* All PHP-based tests for Drupal core are written using the industry-standard
|
|
* PHPUnit framework, with Drupal extensions. There are several categories of
|
|
* tests; each has its own purpose, base class, namespace, and directory:
|
|
* - Unit tests:
|
|
* - Purpose: Test functionality of a class if the Drupal environment
|
|
* (database, settings, etc.) and web browser are not needed for the test,
|
|
* or if the Drupal environment can be replaced by a "mock" object.
|
|
* - Base class: \Drupal\Tests\UnitTestCase
|
|
* - Namespace: \Drupal\Tests\yourmodule\Unit (or a subdirectory)
|
|
* - Directory location: yourmodule/tests/src/Unit (or a subdirectory)
|
|
* - Kernel tests:
|
|
* - Purpose: Test functionality of a class if the full Drupal environment
|
|
* and web browser are not needed for the test, but the functionality has
|
|
* significant Drupal dependencies that cannot easily be mocked. Kernel
|
|
* tests can access services, the database, and a minimal mocked file
|
|
* system, and they use an in-memory pseudo-installation. However, modules
|
|
* are only installed to the point of having services and hooks, unless you
|
|
* install them explicitly.
|
|
* - Base class: \Drupal\KernelTests\KernelTestBase
|
|
* - Namespace: \Drupal\Tests\yourmodule\Kernel (or a subdirectory)
|
|
* - Directory location: yourmodule/tests/src/Kernel (or a subdirectory)
|
|
* - Browser tests:
|
|
* - Purpose: Test functionality with the full Drupal environment and an
|
|
* internal simulated web browser, if JavaScript is not needed.
|
|
* - Base class: \Drupal\Tests\BrowserTestBase
|
|
* - Namespace: \Drupal\Tests\yourmodule\Functional (or a subdirectory)
|
|
* - Directory location: yourmodule/tests/src/Functional (or a subdirectory)
|
|
* - Browser tests with JavaScript:
|
|
* - Purpose: Test functionality with the full Drupal environment and an
|
|
* internal web browser that includes JavaScript execution.
|
|
* - Base class: \Drupal\FunctionalJavascriptTests\WebDriverTestBase
|
|
* - Namespace: \Drupal\Tests\yourmodule\FunctionalJavascript (or a
|
|
* subdirectory)
|
|
* - Directory location: yourmodule/tests/src/FunctionalJavascript (or a
|
|
* subdirectory)
|
|
* - Build tests:
|
|
* - Purpose: Test building processes and their outcomes, such as whether a
|
|
* live update process actually works, or whether a Composer project
|
|
* template actually builds a working site. Provides a temporary build
|
|
* workspace and a PHP-native HTTP server to send requests to the site
|
|
* you've built.
|
|
* - Base class: \Drupal\BuildTests\Framework\BuildTestBase
|
|
* - Namespace: \Drupal\Tests\yourmodule\Build (or a
|
|
* subdirectory)
|
|
* - Directory location: yourmodule/tests/src/Build (or a
|
|
* subdirectory)
|
|
*
|
|
* Some notes about writing PHP test classes:
|
|
* - The class needs a phpDoc comment block with a description and
|
|
* @group annotation, which gives information about the test.
|
|
* - For unit tests, this comment block should also have @coversDefaultClass
|
|
* annotation.
|
|
* - When writing tests, put the test code into public methods, each covering a
|
|
* logical subset of the functionality that is being tested.
|
|
* - The test methods must have names starting with 'test'. For unit tests, the
|
|
* test methods need to have a phpDoc block with @covers annotation telling
|
|
* which class method they are testing.
|
|
* - In some cases, you may need to write a test module to support your test;
|
|
* put such modules under the yourmodule/tests/modules directory.
|
|
*
|
|
* Besides the PHPUnit tests described above, Drupal Core also includes a few
|
|
* JavaScript-only tests, which use the Nightwatch.js framework to test
|
|
* JavaScript code using only JavaScript. These are located in
|
|
* core/tests/Drupal/Nightwatch.
|
|
*
|
|
* For more details, see:
|
|
* - core/tests/README.md for instructions on running tests
|
|
* - https://www.drupal.org/phpunit for full documentation on how to write
|
|
* and run PHPUnit tests for Drupal.
|
|
* - http://phpunit.de for general information on the PHPUnit framework.
|
|
* - @link oo_conventions Object-oriented programming topic @endlink for more
|
|
* on PSR-4, namespaces, and where to place classes.
|
|
* - http://nightwatchjs.org/ for information about Nightwatch testing for
|
|
* JavaScript
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup php_assert PHP Runtime Assert Statements
|
|
* @{
|
|
* Use of the assert() statement in Drupal.
|
|
*
|
|
* Unit tests also use the term "assertion" to refer to test conditions, so to
|
|
* avoid confusion the term "runtime assertion" will be used for the assert()
|
|
* statement throughout the documentation.
|
|
*
|
|
* A runtime assertion is a statement that is expected to always be true at
|
|
* the point in the code it appears at. They are tested using PHP's internal
|
|
* @link http://php.net/assert assert() @endlink statement. If an
|
|
* assertion is ever FALSE it indicates an error in the code or in module or
|
|
* theme configuration files. User-provided configuration files should be
|
|
* verified with standard control structures at all times, not just checked in
|
|
* development environments with assert() statements on.
|
|
*
|
|
* The Drupal project primarily uses runtime assertions to enforce the
|
|
* expectations of the API by failing when incorrect calls are made by code
|
|
* under development. While PHP type hinting does this for objects and arrays,
|
|
* runtime assertions do this for scalars (strings, integers, floats, etc.) and
|
|
* complex data structures such as cache and render arrays. They ensure that
|
|
* methods' return values are the documented data types. They also verify that
|
|
* objects have been properly configured and set up by the service container.
|
|
* They supplement unit tests by checking scenarios that do not have unit tests
|
|
* written for them.
|
|
*
|
|
* There are two php settings which affect runtime assertions. The first,
|
|
* assert.exception, should always be set to 1. The second is zend.assertions.
|
|
* Set this to -1 in production and 1 in development.
|
|
*
|
|
* See https://www.drupal.org/node/2492225 for more information on runtime
|
|
* assertions.
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup info_types Information types
|
|
* @{
|
|
* Types of information in Drupal.
|
|
*
|
|
* Drupal has several distinct types of information, each with its own methods
|
|
* for storage and retrieval:
|
|
* - Content: Information meant to be displayed on your site: articles, basic
|
|
* pages, images, files, custom blocks, etc. Content is stored and accessed
|
|
* using @link entity_api Entities @endlink.
|
|
* - Session: Information about individual users' interactions with the site,
|
|
* such as whether they are logged in. This is really "state" information, but
|
|
* it is not stored the same way so it's a separate type here. Session data is
|
|
* accessed via \Symfony\Component\HttpFoundation\Request::getSession(), which
|
|
* returns an instance of
|
|
* \Symfony\Component\HttpFoundation\Session\SessionInterface.
|
|
* See the @link session Sessions topic @endlink for more information.
|
|
* - State: Information of a temporary nature, generally machine-generated and
|
|
* not human-edited, about the current state of your site. Examples: the time
|
|
* when Cron was last run, whether node access permissions need rebuilding,
|
|
* etc. See @link state_api the State API topic @endlink for more information.
|
|
* - Configuration: Information about your site that is generally (or at least
|
|
* can be) human-edited, but is not Content, and is meant to be relatively
|
|
* permanent. Examples: the name of your site, the content types and views
|
|
* you have defined, etc. See
|
|
* @link config_api the Configuration API topic @endlink for more information.
|
|
*
|
|
* @see cache
|
|
* @see i18n
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup extending Extending and altering Drupal
|
|
* @{
|
|
* Overview of extensions and alteration methods for Drupal.
|
|
*
|
|
* @section sec_types Types of extensions
|
|
* Drupal's core behavior can be extended and altered via these three basic
|
|
* types of extensions:
|
|
* - Themes: Themes alter the appearance of Drupal sites. They can include
|
|
* template files, which alter the HTML markup and other raw output of the
|
|
* site; CSS files, which alter the styling applied to the HTML; and
|
|
* JavaScript, Flash, images, and other files. For more information, see the
|
|
* @link theme_render Theme system and render API topic @endlink and
|
|
* https://www.drupal.org/docs/theming-drupal
|
|
* - Modules: Modules add to or alter the behavior and functionality of Drupal,
|
|
* by using one or more of the methods listed below. For more information
|
|
* about creating modules, see https://www.drupal.org/docs/creating-custom-modules
|
|
* - Installation profiles: Installation profiles can be used to
|
|
* create distributions, which are complete specific-purpose packages of
|
|
* Drupal including additional modules, themes, and data. For more
|
|
* information, see https://www.drupal.org/developing/distributions.
|
|
*
|
|
* @section sec_alter Alteration methods for modules
|
|
* Here is a list of the ways that modules can alter or extend Drupal's core
|
|
* behavior, or the behavior of other modules:
|
|
* - Hooks: Specially-named functions that a module defines, which are
|
|
* discovered and called at specific times, usually to alter behavior or data.
|
|
* See the @link hooks Hooks topic @endlink for more information.
|
|
* - Plugins: Classes that a module defines, which are discovered and
|
|
* instantiated at specific times to add functionality. See the
|
|
* @link plugin_api Plugin API topic @endlink for more information.
|
|
* - Entities: Special plugins that define entity types for storing new types
|
|
* of content or configuration in Drupal. See the
|
|
* @link entity_api Entity API topic @endlink for more information.
|
|
* - Services: Classes that perform basic operations within Drupal, such as
|
|
* accessing the database and sending email. See the
|
|
* @link container Dependency Injection Container and Services topic @endlink
|
|
* for more information.
|
|
* - Routing: Providing or altering "routes", which are URLs that Drupal
|
|
* responds to, or altering routing behavior with event listener classes.
|
|
* See the @link menu Routing and menu topic @endlink for more information.
|
|
* - Events: Modules can register as event subscribers; when an event is
|
|
* dispatched, a method is called on each registered subscriber, allowing each
|
|
* one to react. See the @link events Events topic @endlink for more
|
|
* information.
|
|
*
|
|
* @section sec_sample *.info.yml files
|
|
* Extensions must each be located in a directory whose name matches the short
|
|
* name (or machine name) of the extension, and this directory must contain a
|
|
* file named machine_name.info.yml (where machine_name is the machine name of
|
|
* the extension). See \Drupal\Core\Extension\InfoParserInterface::parse() for
|
|
* documentation of the format of .info.yml files.
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup plugin_api Plugin API
|
|
* @{
|
|
* Using the Plugin API
|
|
*
|
|
* @section sec_overview Overview and terminology
|
|
*
|
|
* The basic idea of plugins is to allow a particular module or subsystem of
|
|
* Drupal to provide functionality in an extensible, object-oriented way. The
|
|
* controlling module or subsystem defines the basic framework (interface) for
|
|
* the functionality, and other modules can create plugins (implementing the
|
|
* interface) with particular behaviors. The controlling module instantiates
|
|
* existing plugins as needed, and calls methods to invoke their functionality.
|
|
* Examples of functionality in Drupal Core that use plugins include: the block
|
|
* system (block types are plugins), the entity/field system (entity types,
|
|
* field types, field formatters, and field widgets are plugins), the image
|
|
* manipulation system (image effects and image toolkits are plugins), and the
|
|
* search system (search page types are plugins).
|
|
*
|
|
* Plugins are grouped into plugin types, each generally defined by an
|
|
* interface. Each plugin type is managed by a plugin manager service, which
|
|
* uses a plugin discovery method to discover provided plugins of that type and
|
|
* instantiate them using a plugin factory.
|
|
*
|
|
* Some plugin types make use of the following concepts or components:
|
|
* - Plugin derivatives: Allows a single plugin class to present itself as
|
|
* multiple plugins. Example: the Menu module provides a block for each
|
|
* defined menu via a block plugin derivative.
|
|
* - Plugin mapping: Allows a plugin class to map a configuration string to an
|
|
* instance, and have the plugin automatically instantiated without writing
|
|
* additional code.
|
|
* - Plugin collections: Provide a way to lazily instantiate a set of plugin
|
|
* instances from a single plugin definition.
|
|
*
|
|
* There are several things a module developer may need to do with plugins:
|
|
* - Define a completely new plugin type: see @ref sec_define below.
|
|
* - Create a plugin of an existing plugin type: see @ref sec_create below.
|
|
* - Perform tasks that involve plugins: see @ref sec_use below.
|
|
*
|
|
* See https://www.drupal.org/developing/api/8/plugins for more detailed
|
|
* documentation on the plugin system. There are also topics for a few
|
|
* of the many existing types of plugins:
|
|
* - @link block_api Block API @endlink
|
|
* - @link entity_api Entity API @endlink
|
|
* - @link field Various types of field-related plugins @endlink
|
|
* - @link views_plugins Views plugins @endlink (has links to topics covering
|
|
* various specific types of Views plugins).
|
|
* - @link search Search page plugins @endlink
|
|
*
|
|
* @section sec_define Defining a new plugin type
|
|
* To define a new plugin type:
|
|
* - Define an interface for the plugin. This describes the common set of
|
|
* behavior, and the methods you will call on each plugin class that is
|
|
* instantiated. Usually this interface will extend one or more of the
|
|
* following interfaces:
|
|
* - \Drupal\Component\Plugin\PluginInspectionInterface
|
|
* - \Drupal\Component\Plugin\ConfigurableInterface
|
|
* - \Drupal\Component\Plugin\DependentPluginInterface
|
|
* - \Drupal\Component\Plugin\ContextAwarePluginInterface
|
|
* - \Drupal\Core\Plugin\PluginFormInterface
|
|
* - \Drupal\Core\Executable\ExecutableInterface
|
|
* - (optional) Create a base class that provides a partial implementation of
|
|
* the interface, for the convenience of developers wishing to create plugins
|
|
* of your type. The base class usually extends
|
|
* \Drupal\Core\Plugin\PluginBase, or one of the base classes that extends
|
|
* this class.
|
|
* - Choose a method for plugin discovery, and define classes as necessary.
|
|
* See @ref sub_discovery below.
|
|
* - Create a plugin manager/factory class and service, which will discover and
|
|
* instantiate plugins. See @ref sub_manager below.
|
|
* - Use the plugin manager to instantiate plugins. Call methods on your plugin
|
|
* interface to perform the tasks of your plugin type.
|
|
* - (optional) If appropriate, define a plugin collection. See @ref
|
|
* sub_collection below for more information.
|
|
*
|
|
* @subsection sub_discovery Plugin discovery
|
|
* Plugin discovery is the process your plugin manager uses to discover the
|
|
* individual plugins of your type that have been defined by your module and
|
|
* other modules. Plugin discovery methods are classes that implement
|
|
* \Drupal\Component\Plugin\Discovery\DiscoveryInterface. Most plugin types use
|
|
* one of the following discovery mechanisms:
|
|
* - Annotation: Plugin classes are annotated and placed in a defined namespace
|
|
* subdirectory. Most Drupal Core plugins use this method of discovery.
|
|
* - Hook: Plugin modules need to implement a hook to tell the manager about
|
|
* their plugins.
|
|
* - YAML: Plugins are listed in YAML files. Drupal Core uses this method for
|
|
* discovering local tasks and local actions. This is mainly useful if all
|
|
* plugins use the same class, so it is kind of like a global derivative.
|
|
* - Static: Plugin classes are registered within the plugin manager class
|
|
* itself. Static discovery is only useful if modules cannot define new
|
|
* plugins of this type (if the list of available plugins is static).
|
|
*
|
|
* It is also possible to define your own custom discovery mechanism or mix
|
|
* methods together. And there are many more details, such as annotation
|
|
* decorators, that apply to some of the discovery methods. See
|
|
* https://www.drupal.org/developing/api/8/plugins for more details.
|
|
*
|
|
* The remainder of this documentation will assume Annotation-based discovery,
|
|
* since this is the most common method.
|
|
*
|
|
* @subsection sub_manager Defining a plugin manager class and service
|
|
* To define an annotation-based plugin manager:
|
|
* - Choose a namespace subdirectory for your plugin. For example, search page
|
|
* plugins go in directory Plugin/Search under the module namespace.
|
|
* - Define an annotation class for your plugin type. This class should extend
|
|
* \Drupal\Component\Annotation\Plugin, and for most plugin types, it should
|
|
* contain member variables corresponding to the annotations plugins will
|
|
* need to provide. All plugins have at least $id: a unique string
|
|
* identifier.
|
|
* - Define an alter hook for altering the discovered plugin definitions. You
|
|
* should document the hook in a *.api.php file.
|
|
* - Define a plugin manager class. This class should implement
|
|
* \Drupal\Component\Plugin\PluginManagerInterface; most plugin managers do
|
|
* this by extending \Drupal\Core\Plugin\DefaultPluginManager. If you do
|
|
* extend the default plugin manager, the only method you will probably need
|
|
* to define is the class constructor, which will need to call the parent
|
|
* constructor to provide information about the annotation class and plugin
|
|
* namespace for discovery, set up the alter hook, and possibly set up
|
|
* caching. See classes that extend DefaultPluginManager for examples.
|
|
* - Define a service for your plugin manager. See the
|
|
* @link container Services topic for more information. @endlink Your service
|
|
* definition should look something like this, referencing your manager
|
|
* class and the parent (default) plugin manager service to inherit
|
|
* constructor arguments:
|
|
* @code
|
|
* plugin.manager.mymodule:
|
|
* class: Drupal\mymodule\MyPluginManager
|
|
* parent: default_plugin_manager
|
|
* @endcode
|
|
* - If your plugin is configurable, you will also need to define the
|
|
* configuration schema and possibly a configuration entity type. See the
|
|
* @link config_api Configuration API topic @endlink for more information.
|
|
*
|
|
* @subsection sub_collection Defining a plugin collection
|
|
* Some configurable plugin types allow administrators to create zero or more
|
|
* instances of each plugin, each with its own configuration. For example,
|
|
* a single block plugin can be configured several times, to display in
|
|
* different regions of a theme, with different visibility settings, a
|
|
* different title, or other plugin-specific settings. To make this possible,
|
|
* a plugin type can make use of what's known as a plugin collection.
|
|
*
|
|
* A plugin collection is a class that extends
|
|
* \Drupal\Component\Plugin\LazyPluginCollection or one of its subclasses; there
|
|
* are several examples in Drupal Core. If your plugin type uses a plugin
|
|
* collection, it will usually also have a configuration entity, and the entity
|
|
* class should implement
|
|
* \Drupal\Core\Entity\EntityWithPluginCollectionInterface. Again, there are
|
|
* several examples in Drupal Core; see also the @link config_api Configuration
|
|
* API topic @endlink for more information about configuration entities.
|
|
*
|
|
* @section sec_create Creating a plugin of an existing type
|
|
* Assuming the plugin type uses annotation-based discovery, in order to create
|
|
* a plugin of an existing type, you will be creating a class. This class must:
|
|
* - Implement the plugin interface, so that it has the required methods
|
|
* defined. Usually, you'll want to extend the plugin base class, if one has
|
|
* been provided.
|
|
* - Have the right annotation in its documentation header. See the
|
|
* @link annotation Annotation topic @endlink for more information about
|
|
* annotation.
|
|
* - Be in the right plugin namespace, in order to be discovered.
|
|
* Often, the easiest way to make sure this happens is to find an existing
|
|
* example of a working plugin class of the desired type, and copy it into your
|
|
* module as a starting point.
|
|
*
|
|
* You can also create a plugin derivative, which allows your plugin class
|
|
* to present itself to the user interface as multiple plugins. To do this,
|
|
* in addition to the plugin class, you'll need to create a separate plugin
|
|
* derivative class implementing
|
|
* \Drupal\Component\Plugin\Derivative\DerivativeInterface. The classes
|
|
* \Drupal\system\Plugin\Block\SystemMenuBlock (plugin class) and
|
|
* \Drupal\system\Plugin\Derivative\SystemMenuBlock (derivative class) are a
|
|
* good example to look at.
|
|
*
|
|
* @section sec_use Performing tasks involving plugins
|
|
* Here are the steps to follow to perform a task that involves plugins:
|
|
* - Locate the machine name of the plugin manager service, and instantiate the
|
|
* service. See the @link container Services topic @endlink for more
|
|
* information on how to do this.
|
|
* - On the plugin manager class, use methods like getDefinition(),
|
|
* getDefinitions(), or other methods specific to particular plugin managers
|
|
* to retrieve information about either specific plugins or the entire list of
|
|
* defined plugins.
|
|
* - Call the createInstance() method on the plugin manager to instantiate
|
|
* individual plugin objects.
|
|
* - Call methods on the plugin objects to perform the desired tasks.
|
|
*
|
|
* @see annotation
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup oo_conventions Objected-oriented programming conventions
|
|
* @{
|
|
* PSR-4, namespaces, class naming, and other conventions.
|
|
*
|
|
* A lot of the PHP code in Drupal is object oriented (OO), making use of
|
|
* @link http://php.net/manual/language.oop5.php PHP classes, interfaces, and traits @endlink
|
|
* (which are loosely referred to as "classes" in the rest of this topic). The
|
|
* following conventions and standards apply to this version of Drupal:
|
|
* - Each class must be in its own file.
|
|
* - Classes must be namespaced. If a module defines a class, the namespace
|
|
* must start with \Drupal\module_name. If it is defined by Drupal Core for
|
|
* use across many modules, the namespace should be \Drupal\Core or
|
|
* \Drupal\Component, with the exception of the global class \Drupal. See
|
|
* https://www.drupal.org/node/1353118 for more about namespaces.
|
|
* - In order for the PSR-4-based class auto-loader to find the class, it must
|
|
* be located in a directory corresponding to the namespace. For
|
|
* module-defined classes, if the namespace is \Drupal\module_name\foo\bar,
|
|
* then the class goes under the main module directory in directory
|
|
* src/foo/bar. For Drupal-wide classes, if the namespace is
|
|
* \Drupal\Core\foo\bar, then it goes in directory
|
|
* core/lib/Drupal/Core/foo/bar. See https://www.drupal.org/node/2156625 for
|
|
* more information about PSR-4.
|
|
* - Some classes have annotations added to their documentation headers. See
|
|
* the @link annotation Annotation topic @endlink for more information.
|
|
* - Standard plugin discovery requires particular namespaces and annotation
|
|
* for most plugin classes. See the
|
|
* @link plugin_api Plugin API topic @endlink for more information.
|
|
* - There are project-wide coding standards for OO code, including naming:
|
|
* https://www.drupal.org/node/608152
|
|
* - Documentation standards for classes are covered on:
|
|
* https://www.drupal.org/coding-standards/docs#classes
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup listing_page_class Page header for Classes page
|
|
* @{
|
|
* Introduction to classes
|
|
*
|
|
* A lot of the PHP code in Drupal is object oriented (OO), making use of
|
|
* @link http://php.net/manual/language.oop5.php PHP classes, interfaces, and traits. @endlink
|
|
* See the
|
|
* @link oo_conventions Objected-oriented programming conventions @endlink
|
|
* for more information.
|
|
*
|
|
* @see oo_conventions
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup listing_page_namespace Page header for Namespaces page
|
|
* @{
|
|
* Introduction to namespaces
|
|
*
|
|
* PHP classes, interfaces, and traits in Drupal are
|
|
* @link http://php.net/manual/language.namespaces.rationale.php namespaced. @endlink
|
|
* See the
|
|
* @link oo_conventions Objected-oriented programming conventions @endlink
|
|
* for more information.
|
|
*
|
|
* @see oo_conventions
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup best_practices Best practices for developers
|
|
* @{
|
|
* Overview of standards and best practices for developers
|
|
*
|
|
* Ideally, all code that is included in Drupal Core and contributed modules,
|
|
* themes, and distributions will be secure, internationalized, maintainable,
|
|
* and efficient. In order to facilitate this, the Drupal community has
|
|
* developed a set of guidelines and standards for developers to follow. Most of
|
|
* these standards can be found under
|
|
* @link https://www.drupal.org/developing/best-practices Best practices on Drupal.org @endlink
|
|
*
|
|
* Standards and best practices that developers should be aware of include:
|
|
* - Security: https://www.drupal.org/writing-secure-code and the
|
|
* @link sanitization Sanitization functions topic @endlink
|
|
* - Coding standards: https://www.drupal.org/coding-standards
|
|
* and https://www.drupal.org/coding-standards/docs
|
|
* - Accessibility: https://www.drupal.org/node/1637990 (modules) and
|
|
* https://www.drupal.org/node/464472 (themes)
|
|
* - Usability: https://www.drupal.org/ui-standards
|
|
* - Internationalization: @link i18n Internationalization topic @endlink
|
|
* - Automated testing: @link testing Automated tests topic @endlink
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup utility Utility classes and functions
|
|
* @{
|
|
* Overview of utility classes and functions for developers.
|
|
*
|
|
* Drupal provides developers with a variety of utility functions that make it
|
|
* easier and more efficient to perform tasks that are either really common,
|
|
* tedious, or difficult. Utility functions help to reduce code duplication and
|
|
* should be used in place of one-off code whenever possible.
|
|
*
|
|
* @see common.inc
|
|
* @see file
|
|
* @see format
|
|
* @see php_wrappers
|
|
* @see sanitization
|
|
* @see transliteration
|
|
* @see validation
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup hooks Hooks
|
|
* @{
|
|
* Define functions that alter the behavior of Drupal core.
|
|
*
|
|
* One way for modules to alter the core behavior of Drupal (or another module)
|
|
* is to use hooks. Hooks are specially-named functions that a module defines
|
|
* (this is known as "implementing the hook"), which are discovered and called
|
|
* at specific times to alter or add to the base behavior or data (this is
|
|
* known as "invoking the hook"). Each hook has a name (example:
|
|
* hook_batch_alter()), a defined set of parameters, and a defined return value.
|
|
* Your modules can implement hooks that are defined by Drupal core or other
|
|
* modules that they interact with. Your modules can also define their own
|
|
* hooks, in order to let other modules interact with them.
|
|
*
|
|
* To implement a hook:
|
|
* - Locate the documentation for the hook. Hooks are documented in *.api.php
|
|
* files, by defining functions whose name starts with "hook_" (these
|
|
* files and their functions are never loaded by Drupal -- they exist solely
|
|
* for documentation). The function should have a documentation header, as
|
|
* well as a sample function body. For example, in the core file form.api.php,
|
|
* you can find hooks such as hook_batch_alter(). Also, if you are viewing
|
|
* this documentation on an API reference site, the Core hooks will be listed
|
|
* in this topic.
|
|
* - Copy the function to your module's .module file.
|
|
* - Change the name of the function, substituting your module's short name
|
|
* (name of the module's directory, and .info.yml file without the extension)
|
|
* for the "hook" part of the sample function name. For instance, to implement
|
|
* hook_batch_alter(), you would rename it to my_module_batch_alter().
|
|
* - Edit the documentation for the function (normally, your implementation
|
|
* should just have one line saying "Implements hook_batch_alter().").
|
|
* - Edit the body of the function, substituting in what you need your module
|
|
* to do.
|
|
*
|
|
* To define a hook:
|
|
* - Choose a unique name for your hook. It should start with "hook_", followed
|
|
* by your module's short name.
|
|
* - Provide documentation in a *.api.php file in your module's main
|
|
* directory. See the "implementing" section above for details of what this
|
|
* should contain (parameters, return value, and sample function body).
|
|
* - Invoke the hook in your module's code.
|
|
*
|
|
* To invoke a hook, use methods on
|
|
* \Drupal\Core\Extension\ModuleHandlerInterface such as alter(), invoke(),
|
|
* and invokeAll(). You can obtain a module handler by calling
|
|
* \Drupal::moduleHandler(), or getting the 'module_handler' service on an
|
|
* injected container.
|
|
*
|
|
* @see extending
|
|
* @see themeable
|
|
* @see callbacks
|
|
* @see \Drupal\Core\Extension\ModuleHandlerInterface
|
|
* @see \Drupal::moduleHandler()
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup callbacks Callbacks
|
|
* @{
|
|
* Callback function signatures.
|
|
*
|
|
* Drupal's API sometimes uses callback functions to allow you to define how
|
|
* some type of processing happens. A callback is a function with a defined
|
|
* signature, which you define in a module. Then you pass the function name as
|
|
* a parameter to a Drupal API function or return it as part of a hook
|
|
* implementation return value, and your function is called at an appropriate
|
|
* time. For instance, when setting up batch processing you might need to
|
|
* provide a callback function for each processing step and/or a callback for
|
|
* when processing is finished; you would do that by defining these functions
|
|
* and passing their names into the batch setup function.
|
|
*
|
|
* Callback function signatures, like hook definitions, are described by
|
|
* creating and documenting dummy functions in a *.api.php file; normally, the
|
|
* dummy callback function's name should start with "callback_", and you should
|
|
* document the parameters and return value and provide a sample function body.
|
|
* Then your API documentation can refer to this callback function in its
|
|
* documentation. A user of your API can usually name their callback function
|
|
* anything they want, although a standard name would be to replace "callback_"
|
|
* with the module name.
|
|
*
|
|
* @see hooks
|
|
* @see themeable
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup form_api Form generation
|
|
* @{
|
|
* Describes how to generate and manipulate forms and process form submissions.
|
|
*
|
|
* Drupal provides a Form API in order to achieve consistency in its form
|
|
* processing and presentation, while simplifying code and reducing the amount
|
|
* of HTML that must be explicitly generated by a module.
|
|
*
|
|
* @section generating_forms Creating forms
|
|
* Forms are defined as classes that implement the
|
|
* \Drupal\Core\Form\FormInterface and are built using the
|
|
* \Drupal\Core\Form\FormBuilder class. Drupal provides a couple of utility
|
|
* classes that can be extended as a starting point for most basic forms, the
|
|
* most commonly used of which is \Drupal\Core\Form\FormBase. FormBuilder
|
|
* handles the low level processing of forms such as rendering the necessary
|
|
* HTML, initial processing of incoming $_POST data, and delegating to your
|
|
* implementation of FormInterface for validation and processing of submitted
|
|
* data.
|
|
*
|
|
* Here is an example of a Form class:
|
|
* @code
|
|
* namespace Drupal\mymodule\Form;
|
|
*
|
|
* use Drupal\Core\Form\FormBase;
|
|
* use Drupal\Core\Form\FormStateInterface;
|
|
*
|
|
* class ExampleForm extends FormBase {
|
|
* public function getFormId() {
|
|
* // Unique ID of the form.
|
|
* return 'example_form';
|
|
* }
|
|
*
|
|
* public function buildForm(array $form, FormStateInterface $form_state) {
|
|
* // Create a $form API array.
|
|
* $form['phone_number'] = array(
|
|
* '#type' => 'tel',
|
|
* '#title' => $this->t('Your phone number'),
|
|
* );
|
|
* $form['save'] = array(
|
|
* '#type' => 'submit',
|
|
* '#value' => $this->t('Save'),
|
|
* );
|
|
* return $form;
|
|
* }
|
|
*
|
|
* public function validateForm(array &$form, FormStateInterface $form_state) {
|
|
* // Validate submitted form data.
|
|
* }
|
|
*
|
|
* public function submitForm(array &$form, FormStateInterface $form_state) {
|
|
* // Handle submitted form data.
|
|
* }
|
|
* }
|
|
* @endcode
|
|
*
|
|
* @section retrieving_forms Retrieving and displaying forms
|
|
* \Drupal::formBuilder()->getForm() should be used to handle retrieving,
|
|
* processing, and displaying a rendered HTML form. Given the ExampleForm
|
|
* defined above,
|
|
* \Drupal::formBuilder()->getForm('Drupal\mymodule\Form\ExampleForm') would
|
|
* return the rendered HTML of the form defined by ExampleForm::buildForm(), or
|
|
* call the validateForm() and submitForm(), methods depending on the current
|
|
* processing state.
|
|
*
|
|
* The argument to \Drupal::formBuilder()->getForm() is the name of a class that
|
|
* implements FormInterface. Any additional arguments passed to the getForm()
|
|
* method will be passed along as additional arguments to the
|
|
* ExampleForm::buildForm() method.
|
|
*
|
|
* For example:
|
|
* @code
|
|
* $extra = '612-123-4567';
|
|
* $form = \Drupal::formBuilder()->getForm('Drupal\mymodule\Form\ExampleForm', $extra);
|
|
* ...
|
|
* public function buildForm(array $form, FormStateInterface $form_state, $extra = NULL)
|
|
* $form['phone_number'] = array(
|
|
* '#type' => 'tel',
|
|
* '#title' => $this->t('Your phone number'),
|
|
* '#value' => $extra,
|
|
* );
|
|
* return $form;
|
|
* }
|
|
* @endcode
|
|
*
|
|
* Alternatively, forms can be built directly via the routing system which will
|
|
* take care of calling \Drupal::formBuilder()->getForm(). The following example
|
|
* demonstrates the use of a routing.yml file to display a form at the given
|
|
* route.
|
|
*
|
|
* @code
|
|
* example.form:
|
|
* path: '/example-form'
|
|
* defaults:
|
|
* _title: 'Example form'
|
|
* _form: '\Drupal\mymodule\Form\ExampleForm'
|
|
* @endcode
|
|
*
|
|
* The $form argument to form-related functions is a specialized render array
|
|
* containing the elements and properties of the form. For more about render
|
|
* arrays, see the @link theme_render Render API topic. @endlink For more
|
|
* detailed explanations of the Form API workflow, see the
|
|
* @link https://www.drupal.org/node/2117411 Form API documentation section. @endlink
|
|
* In addition, there is a set of Form API tutorials in the
|
|
* @link https://www.drupal.org/project/examples Examples for Developers project. @endlink
|
|
*
|
|
* In the form builder, validation, submission, and other form methods,
|
|
* $form_state is the primary influence on the processing of the form and is
|
|
* passed to most methods, so they can use it to communicate with the form
|
|
* system and each other. $form_state is an object that implements
|
|
* \Drupal\Core\Form\FormStateInterface.
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup queue Queue operations
|
|
* @{
|
|
* Queue items to allow later processing.
|
|
*
|
|
* The queue system allows placing items in a queue and processing them later.
|
|
* The system tries to ensure that only one consumer can process an item.
|
|
*
|
|
* Before a queue can be used it needs to be created by
|
|
* Drupal\Core\Queue\QueueInterface::createQueue().
|
|
*
|
|
* Items can be added to the queue by passing an arbitrary data object to
|
|
* Drupal\Core\Queue\QueueInterface::createItem().
|
|
*
|
|
* To process an item, call Drupal\Core\Queue\QueueInterface::claimItem() and
|
|
* specify how long you want to have a lease for working on that item.
|
|
* When finished processing, the item needs to be deleted by calling
|
|
* Drupal\Core\Queue\QueueInterface::deleteItem(). If the consumer dies, the
|
|
* item will be made available again by the Drupal\Core\Queue\QueueInterface
|
|
* implementation once the lease expires. Another consumer will then be able to
|
|
* receive it when calling Drupal\Core\Queue\QueueInterface::claimItem().
|
|
* Due to this, the processing code should be aware that an item might be handed
|
|
* over for processing more than once.
|
|
*
|
|
* The $item object used by the Drupal\Core\Queue\QueueInterface can contain
|
|
* arbitrary metadata depending on the implementation. Systems using the
|
|
* interface should only rely on the data property which will contain the
|
|
* information passed to Drupal\Core\Queue\QueueInterface::createItem().
|
|
* The full queue item returned by Drupal\Core\Queue\QueueInterface::claimItem()
|
|
* needs to be passed to Drupal\Core\Queue\QueueInterface::deleteItem() once
|
|
* processing is completed.
|
|
*
|
|
* There are two kinds of queue backends available: reliable, which preserves
|
|
* the order of messages and guarantees that every item will be executed at
|
|
* least once. The non-reliable kind only does a best effort to preserve order
|
|
* in messages and to execute them at least once but there is a small chance
|
|
* that some items get lost. For example, some distributed back-ends like
|
|
* Amazon SQS will be managing jobs for a large set of producers and consumers
|
|
* where a strict FIFO ordering will likely not be preserved. Another example
|
|
* would be an in-memory queue backend which might lose items if it crashes.
|
|
* However, such a backend would be able to deal with significantly more writes
|
|
* than a reliable queue and for many tasks this is more important. See
|
|
* aggregator_cron() for an example of how to effectively use a non-reliable
|
|
* queue. Another example is doing Twitter statistics -- the small possibility
|
|
* of losing a few items is insignificant next to power of the queue being able
|
|
* to keep up with writes. As described in the processing section, regardless
|
|
* of the queue being reliable or not, the processing code should be aware that
|
|
* an item might be handed over for processing more than once (because the
|
|
* processing code might time out before it finishes).
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup annotation Annotations
|
|
* @{
|
|
* Annotations for class discovery and metadata description.
|
|
*
|
|
* The Drupal plugin system has a set of reusable components that developers
|
|
* can use, override, and extend in their modules. Most of the plugins use
|
|
* annotations, which let classes register themselves as plugins and describe
|
|
* their metadata. (Annotations can also be used for other purposes, though
|
|
* at the moment, Drupal only uses them for the plugin system.)
|
|
*
|
|
* To annotate a class as a plugin, add code similar to the following to the
|
|
* end of the documentation block immediately preceding the class declaration:
|
|
* @code
|
|
* * @ContentEntityType(
|
|
* * id = "comment",
|
|
* * label = @Translation("Comment"),
|
|
* * ...
|
|
* * base_table = "comment"
|
|
* * )
|
|
* @endcode
|
|
*
|
|
* Note that you must use double quotes; single quotes will not work in
|
|
* annotations.
|
|
*
|
|
* Some annotation types, which extend the "@ PluginID" annotation class, have
|
|
* only a single 'id' key in their annotation. For these, it is possible to use
|
|
* a shorthand annotation. For example:
|
|
* @code
|
|
* * @ViewsArea("entity")
|
|
* @endcode
|
|
* in place of
|
|
* @code
|
|
* * @ViewsArea(
|
|
* * id = "entity"
|
|
* *)
|
|
* @endcode
|
|
*
|
|
* The available annotation classes are listed in this topic, and can be
|
|
* identified when you are looking at the Drupal source code by having
|
|
* "@ Annotation" in their documentation blocks (without the space after @). To
|
|
* find examples of annotation for a particular annotation class, such as
|
|
* EntityType, look for class files that have an @ annotation section using the
|
|
* annotation class.
|
|
*
|
|
* @see plugin_translatable
|
|
* @see plugin_context
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @addtogroup hooks
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* Perform periodic actions.
|
|
*
|
|
* Modules that require some commands to be executed periodically can
|
|
* implement hook_cron(). The engine will then call the hook whenever a cron
|
|
* run happens, as defined by the administrator. Typical tasks managed by
|
|
* hook_cron() are database maintenance, backups, recalculation of settings
|
|
* or parameters, automated mailing, and retrieving remote data.
|
|
*
|
|
* Short-running or non-resource-intensive tasks can be executed directly in
|
|
* the hook_cron() implementation.
|
|
*
|
|
* Long-running tasks and tasks that could time out, such as retrieving remote
|
|
* data, sending email, and intensive file tasks, should use the queue API
|
|
* instead of executing the tasks directly. To do this, first define one or
|
|
* more queues via a \Drupal\Core\Annotation\QueueWorker plugin. Then, add items
|
|
* that need to be processed to the defined queues.
|
|
*/
|
|
function hook_cron() {
|
|
// Short-running operation example, not using a queue:
|
|
// Delete all expired records since the last cron run.
|
|
$expires = \Drupal::state()->get('mymodule.last_check', 0);
|
|
$request_time = \Drupal::time()->getRequestTime();
|
|
\Drupal::database()->delete('mymodule_table')
|
|
->condition('expires', $expires, '>=')
|
|
->execute();
|
|
\Drupal::state()->set('mymodule.last_check', $request_time);
|
|
|
|
// Long-running operation example, leveraging a queue:
|
|
// Queue news feeds for updates once their refresh interval has elapsed.
|
|
$queue = \Drupal::queue('aggregator_feeds');
|
|
$ids = \Drupal::entityTypeManager()->getStorage('aggregator_feed')->getFeedIdsToRefresh();
|
|
foreach (Feed::loadMultiple($ids) as $feed) {
|
|
if ($queue->createItem($feed)) {
|
|
// Add timestamp to avoid queueing item more than once.
|
|
$feed->setQueuedTime($request_time);
|
|
$feed->save();
|
|
}
|
|
}
|
|
$ids = \Drupal::entityQuery('aggregator_feed')
|
|
->accessCheck(FALSE)
|
|
->condition('queued', $request_time - (3600 * 6), '<')
|
|
->execute();
|
|
if ($ids) {
|
|
$feeds = Feed::loadMultiple($ids);
|
|
foreach ($feeds as $feed) {
|
|
$feed->setQueuedTime(0);
|
|
$feed->save();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Alter available data types for typed data wrappers.
|
|
*
|
|
* @param array $data_types
|
|
* An array of data type information.
|
|
*
|
|
* @see hook_data_type_info()
|
|
*/
|
|
function hook_data_type_info_alter(&$data_types) {
|
|
$data_types['email']['class'] = '\Drupal\mymodule\Type\Email';
|
|
}
|
|
|
|
/**
|
|
* Alter cron queue information before cron runs.
|
|
*
|
|
* Called by \Drupal\Core\Cron to allow modules to alter cron queue settings
|
|
* before any jobs are processed.
|
|
*
|
|
* @param array $queues
|
|
* An array of cron queue information.
|
|
*
|
|
* @see \Drupal\Core\Queue\QueueWorkerInterface
|
|
* @see \Drupal\Core\Annotation\QueueWorker
|
|
* @see \Drupal\Core\Cron
|
|
*/
|
|
function hook_queue_info_alter(&$queues) {
|
|
// This site has many feeds so let's spend 90 seconds on each cron run
|
|
// updating feeds instead of the default 60.
|
|
$queues['aggregator_feeds']['cron']['time'] = 90;
|
|
}
|
|
|
|
/**
|
|
* Alter an email message created with MailManagerInterface->mail().
|
|
*
|
|
* Hook hook_mail_alter() allows modification of email messages created and sent
|
|
* with MailManagerInterface->mail(). Usage examples include adding and/or
|
|
* changing message text, message fields, and message headers.
|
|
*
|
|
* Email messages sent using functions other than MailManagerInterface->mail()
|
|
* will not invoke hook_mail_alter(). For example, a contributed module directly
|
|
* calling the MailInterface->mail() or PHP mail() function will not invoke
|
|
* this hook. All core modules use MailManagerInterface->mail() for messaging,
|
|
* it is best practice but not mandatory in contributed modules.
|
|
*
|
|
* @param $message
|
|
* An array containing the message data. Keys in this array include:
|
|
* - 'id':
|
|
* The MailManagerInterface->mail() id of the message. Look at module source
|
|
* code or MailManagerInterface->mail() for possible id values.
|
|
* - 'to':
|
|
* The address or addresses the message will be sent to. The
|
|
* formatting of this string must comply with RFC 2822.
|
|
* - 'from':
|
|
* The address the message will be marked as being from, which is
|
|
* either a custom address or the site-wide default email address.
|
|
* - 'subject':
|
|
* Subject of the email to be sent. This must not contain any newline
|
|
* characters, or the email may not be sent properly.
|
|
* - 'body':
|
|
* An array of strings or objects that implement
|
|
* \Drupal\Component\Render\MarkupInterface containing the message text. The
|
|
* message body is created by concatenating the individual array strings
|
|
* into a single text string using "\n\n" as a separator.
|
|
* - 'headers':
|
|
* Associative array containing mail headers, such as From, Sender,
|
|
* MIME-Version, Content-Type, etc.
|
|
* - 'params':
|
|
* An array of optional parameters supplied by the caller of
|
|
* MailManagerInterface->mail() that is used to build the message before
|
|
* hook_mail_alter() is invoked.
|
|
* - 'language':
|
|
* The language object used to build the message before hook_mail_alter()
|
|
* is invoked.
|
|
* - 'send':
|
|
* Set to FALSE to abort sending this email message.
|
|
*
|
|
* @see \Drupal\Core\Mail\MailManagerInterface::mail()
|
|
*/
|
|
function hook_mail_alter(&$message) {
|
|
if ($message['id'] == 'modulename_messagekey') {
|
|
if (!example_notifications_optin($message['to'], $message['id'])) {
|
|
// If the recipient has opted to not receive such messages, cancel
|
|
// sending.
|
|
$message['send'] = FALSE;
|
|
return;
|
|
}
|
|
$message['body'][] = "--\nMail sent out from " . \Drupal::config('system.site')->get('name');
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Prepares a message based on parameters.
|
|
*
|
|
* This hook is called from MailManagerInterface->mail(). Note that hook_mail(),
|
|
* unlike hook_mail_alter(), is only called on the $module argument to
|
|
* MailManagerInterface->mail(), not all modules.
|
|
*
|
|
* @param $key
|
|
* An identifier of the mail.
|
|
* @param $message
|
|
* An array to be filled in. Elements in this array include:
|
|
* - id: An ID to identify the mail sent. Look at module source code or
|
|
* MailManagerInterface->mail() for possible id values.
|
|
* - to: The address or addresses the message will be sent to. The
|
|
* formatting of this string must comply with RFC 2822.
|
|
* - subject: Subject of the email to be sent. This must not contain any
|
|
* newline characters, or the mail may not be sent properly.
|
|
* MailManagerInterface->mail() sets this to an empty
|
|
* string when the hook is invoked.
|
|
* - body: An array of lines containing the message to be sent. Drupal will
|
|
* format the correct line endings for you. MailManagerInterface->mail()
|
|
* sets this to an empty array when the hook is invoked. The array may
|
|
* contain either strings or objects implementing
|
|
* \Drupal\Component\Render\MarkupInterface.
|
|
* - from: The address the message will be marked as being from, which is
|
|
* set by MailManagerInterface->mail() to either a custom address or the
|
|
* site-wide default email address when the hook is invoked.
|
|
* - headers: Associative array containing mail headers, such as From,
|
|
* Sender, MIME-Version, Content-Type, etc.
|
|
* MailManagerInterface->mail() pre-fills several headers in this array.
|
|
* @param $params
|
|
* An array of parameters supplied by the caller of
|
|
* MailManagerInterface->mail().
|
|
*
|
|
* @see \Drupal\Core\Mail\MailManagerInterface::mail()
|
|
*/
|
|
function hook_mail($key, &$message, $params) {
|
|
$account = $params['account'];
|
|
$context = $params['context'];
|
|
$variables = [
|
|
'%site_name' => \Drupal::config('system.site')->get('name'),
|
|
'%username' => $account->getDisplayName(),
|
|
];
|
|
if ($context['hook'] == 'taxonomy') {
|
|
$entity = $params['entity'];
|
|
$vocabulary = Vocabulary::load($entity->id());
|
|
$variables += [
|
|
'%term_name' => $entity->name,
|
|
'%term_description' => $entity->description,
|
|
'%term_id' => $entity->id(),
|
|
'%vocabulary_name' => $vocabulary->label(),
|
|
'%vocabulary_description' => $vocabulary->getDescription(),
|
|
'%vocabulary_id' => $vocabulary->id(),
|
|
];
|
|
}
|
|
|
|
// Node-based variable translation is only available if we have a node.
|
|
if (isset($params['node'])) {
|
|
/** @var \Drupal\node\NodeInterface $node */
|
|
$node = $params['node'];
|
|
$variables += [
|
|
'%uid' => $node->getOwnerId(),
|
|
'%url' => $node->toUrl('canonical', ['absolute' => TRUE])->toString(),
|
|
'%node_type' => node_get_type_label($node),
|
|
'%title' => $node->getTitle(),
|
|
'%teaser' => $node->teaser,
|
|
'%body' => $node->body,
|
|
];
|
|
}
|
|
$subject = strtr($context['subject'], $variables);
|
|
$body = strtr($context['message'], $variables);
|
|
$message['subject'] .= str_replace(["\r", "\n"], '', $subject);
|
|
$message['body'][] = MailFormatHelper::htmlToText($body);
|
|
}
|
|
|
|
/**
|
|
* Alter the list of mail backend plugin definitions.
|
|
*
|
|
* @param array $info
|
|
* The mail backend plugin definitions to be altered.
|
|
*
|
|
* @see \Drupal\Core\Annotation\Mail
|
|
* @see \Drupal\Core\Mail\MailManager
|
|
*/
|
|
function hook_mail_backend_info_alter(&$info) {
|
|
unset($info['test_mail_collector']);
|
|
}
|
|
|
|
/**
|
|
* Alter the default country list.
|
|
*
|
|
* @param $countries
|
|
* The associative array of countries keyed by two-letter country code.
|
|
*
|
|
* @see \Drupal\Core\Locale\CountryManager::getList()
|
|
*/
|
|
function hook_countries_alter(&$countries) {
|
|
// Elbonia is now independent, so add it to the country list.
|
|
$countries['EB'] = 'Elbonia';
|
|
}
|
|
|
|
/**
|
|
* Alter display variant plugin definitions.
|
|
*
|
|
* @param array $definitions
|
|
* The array of display variant definitions, keyed by plugin ID.
|
|
*
|
|
* @see \Drupal\Core\Display\VariantManager
|
|
* @see \Drupal\Core\Display\Annotation\DisplayVariant
|
|
*/
|
|
function hook_display_variant_plugin_alter(array &$definitions) {
|
|
$definitions['full_page']['admin_label'] = t('Block layout');
|
|
}
|
|
|
|
/**
|
|
* Allow modules to alter layout plugin definitions.
|
|
*
|
|
* @param \Drupal\Core\Layout\LayoutDefinition[] $definitions
|
|
* The array of layout definitions, keyed by plugin ID.
|
|
*/
|
|
function hook_layout_alter(&$definitions) {
|
|
// Remove a layout.
|
|
unset($definitions['twocol']);
|
|
}
|
|
|
|
/**
|
|
* Flush all persistent and static caches.
|
|
*
|
|
* This hook asks your module to clear all of its static caches,
|
|
* in order to ensure a clean environment for subsequently
|
|
* invoked data rebuilds.
|
|
*
|
|
* Do NOT use this hook for rebuilding information. Only use it to flush custom
|
|
* caches.
|
|
*
|
|
* Static caches using drupal_static() do not need to be reset manually.
|
|
* However, all other static variables that do not use drupal_static() must be
|
|
* manually reset.
|
|
*
|
|
* This hook is invoked by drupal_flush_all_caches(). It runs before module data
|
|
* is updated and before hook_rebuild().
|
|
*
|
|
* @see drupal_flush_all_caches()
|
|
* @see hook_rebuild()
|
|
*/
|
|
function hook_cache_flush() {
|
|
if (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update') {
|
|
_update_cache_clear();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Rebuild data based upon refreshed caches.
|
|
*
|
|
* This hook allows your module to rebuild its data based on the latest/current
|
|
* module data. It runs after hook_cache_flush() and after all module data has
|
|
* been updated.
|
|
*
|
|
* This hook is only invoked after the system has been completely cleared;
|
|
* i.e., all previously cached data is known to be gone and every API in the
|
|
* system is known to return current information, so your module can safely rely
|
|
* on all available data to rebuild its own.
|
|
*
|
|
* @see hook_cache_flush()
|
|
* @see drupal_flush_all_caches()
|
|
*/
|
|
function hook_rebuild() {
|
|
$themes = \Drupal::service('theme_handler')->listInfo();
|
|
foreach ($themes as $theme) {
|
|
_block_rehash($theme->getName());
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Alter the configuration synchronization steps.
|
|
*
|
|
* @param array $sync_steps
|
|
* A one-dimensional array of \Drupal\Core\Config\ConfigImporter method names
|
|
* or callables that are invoked to complete the import, in the order that
|
|
* they will be processed. Each callable item defined in $sync_steps should
|
|
* either be a global function or a public static method. The callable should
|
|
* accept a $context array by reference. For example:
|
|
* @code
|
|
* function _additional_configuration_step(&$context) {
|
|
* // Do stuff.
|
|
* // If finished set $context['finished'] = 1.
|
|
* }
|
|
* @endcode
|
|
* For more information on creating batches, see the
|
|
* @link batch Batch operations @endlink documentation.
|
|
*
|
|
* @see callback_batch_operation()
|
|
* @see \Drupal\Core\Config\ConfigImporter::initialize()
|
|
*/
|
|
function hook_config_import_steps_alter(&$sync_steps, \Drupal\Core\Config\ConfigImporter $config_importer) {
|
|
$deletes = $config_importer->getUnprocessedConfiguration('delete');
|
|
if (isset($deletes['field.storage.node.body'])) {
|
|
$sync_steps[] = '_additional_configuration_step';
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Alter config typed data definitions.
|
|
*
|
|
* For example you can alter the typed data types representing each
|
|
* configuration schema type to change default labels or form element renderers
|
|
* used for configuration translation.
|
|
*
|
|
* If implementations of this hook add or remove configuration schema a
|
|
* ConfigSchemaAlterException will be thrown. Keep in mind that there are tools
|
|
* that may use the configuration schema for static analysis of configuration
|
|
* files, like the string extractor for the localization system. Such systems
|
|
* won't work with dynamically defined configuration schemas.
|
|
*
|
|
* For adding new data types use configuration schema YAML files instead.
|
|
*
|
|
* @param $definitions
|
|
* Associative array of configuration type definitions keyed by schema type
|
|
* names. The elements are themselves array with information about the type.
|
|
*
|
|
* @see \Drupal\Core\Config\TypedConfigManager
|
|
* @see \Drupal\Core\Config\Schema\ConfigSchemaAlterException
|
|
*/
|
|
function hook_config_schema_info_alter(&$definitions) {
|
|
// Enhance the text and date type definitions with classes to generate proper
|
|
// form elements in ConfigTranslationFormBase. Other translatable types will
|
|
// appear as a one line textfield.
|
|
$definitions['text']['form_element_class'] = '\Drupal\config_translation\FormElement\Textarea';
|
|
$definitions['date_format']['form_element_class'] = '\Drupal\config_translation\FormElement\DateFormat';
|
|
}
|
|
|
|
/**
|
|
* Alter validation constraint plugin definitions.
|
|
*
|
|
* @param array[] $definitions
|
|
* The array of validation constraint definitions, keyed by plugin ID.
|
|
*
|
|
* @see \Drupal\Core\Validation\ConstraintManager
|
|
* @see \Drupal\Core\Validation\Annotation\Constraint
|
|
*/
|
|
function hook_validation_constraint_alter(array &$definitions) {
|
|
$definitions['Null']['class'] = '\Drupal\mymodule\Plugin\Validation\Constraints\MyClass';
|
|
}
|
|
|
|
/**
|
|
* @} End of "addtogroup hooks".
|
|
*/
|
|
|
|
/**
|
|
* @defgroup ajax Ajax API
|
|
* @{
|
|
* Overview for Drupal's Ajax API.
|
|
*
|
|
* @section sec_overview Overview of Ajax
|
|
* Ajax is the process of dynamically updating parts of a page's HTML based on
|
|
* data from the server. When a specified event takes place, a PHP callback is
|
|
* triggered, which performs server-side logic and may return updated markup or
|
|
* JavaScript commands to run. After the return, the browser runs the JavaScript
|
|
* or updates the markup on the fly, with no full page refresh necessary.
|
|
*
|
|
* Many different events can trigger Ajax responses, including:
|
|
* - Clicking a button
|
|
* - Pressing a key
|
|
* - Moving the mouse
|
|
*
|
|
* @section sec_framework Ajax responses in forms
|
|
* Forms that use the Drupal Form API (see the
|
|
* @link form_api Form API topic @endlink for more information about forms) can
|
|
* trigger AJAX responses. Here is an outline of the steps:
|
|
* - Add property '#ajax' to a form element in your form array, to trigger an
|
|
* Ajax response.
|
|
* - Write an Ajax callback to process the input and respond.
|
|
* See sections below for details on these two steps.
|
|
*
|
|
* @subsection sub_form Adding Ajax triggers to a form
|
|
* As an example of adding Ajax triggers to a form, consider editing a date
|
|
* format, where the user is provided with a sample of the generated date output
|
|
* as they type. To accomplish this, typing in the text field should trigger an
|
|
* Ajax response. This is done in the text field form array element
|
|
* in \Drupal\config_translation\FormElement\DateFormat::getFormElement():
|
|
* @code
|
|
* '#ajax' => array(
|
|
* 'callback' => 'Drupal\config_translation\FormElement\DateFormat::ajaxSample',
|
|
* 'event' => 'keyup',
|
|
* 'progress' => array(
|
|
* 'type' => 'throbber',
|
|
* 'message' => NULL,
|
|
* ),
|
|
* ),
|
|
* @endcode
|
|
*
|
|
* As you can see from this example, the #ajax property for a form element is
|
|
* an array. Here are the details of its elements, all of which are optional:
|
|
* - callback: The callback to invoke to handle the server side of the
|
|
* Ajax event. More information on callbacks is below in @ref sub_callback.
|
|
* - wrapper: The HTML 'id' attribute of the area where the content returned by
|
|
* the callback should be placed. Note that callbacks have a choice of
|
|
* returning content or JavaScript commands; 'wrapper' is used for content
|
|
* returns.
|
|
* - method: The jQuery method for placing the new content (used with
|
|
* 'wrapper'). Valid options are 'replaceWith' (default), 'append', 'prepend',
|
|
* 'before', 'after', or 'html'. See
|
|
* http://api.jquery.com/category/manipulation/ for more information on these
|
|
* methods.
|
|
* - effect: The jQuery effect to use when placing the new HTML (used with
|
|
* 'wrapper'). Valid options are 'none' (default), 'slide', or 'fade'.
|
|
* - speed: The effect speed to use (used with 'effect' and 'wrapper'). Valid
|
|
* options are 'slow' (default), 'fast', or the number of milliseconds the
|
|
* effect should run.
|
|
* - event: The JavaScript event to respond to. This is selected automatically
|
|
* for the type of form element; provide a value to override the default.
|
|
* - prevent: A JavaScript event to prevent when the event is triggered. For
|
|
* example, if you use event 'mousedown' on a button, you might want to
|
|
* prevent 'click' events from also being triggered.
|
|
* - progress: An array indicating how to show Ajax processing progress. Can
|
|
* contain one or more of these elements:
|
|
* - type: Type of indicator: 'throbber' (default) or 'bar'.
|
|
* - message: Translated message to display.
|
|
* - url: For a bar progress indicator, URL path for determining progress.
|
|
* - interval: For a bar progress indicator, how often to update it.
|
|
* - url: A \Drupal\Core\Url to which to submit the Ajax request. If omitted,
|
|
* defaults to either the same URL as the form or link destination is for
|
|
* someone with JavaScript disabled, or a slightly modified version (e.g.,
|
|
* with a query parameter added, removed, or changed) of that URL if
|
|
* necessary to support Drupal's content negotiation. It is recommended to
|
|
* omit this key and use Drupal's content negotiation rather than using
|
|
* substantially different URLs between Ajax and non-Ajax.
|
|
*
|
|
* @subsection sub_callback Setting up a callback to process Ajax
|
|
* Once you have set up your form to trigger an Ajax response (see @ref sub_form
|
|
* above), you need to write some PHP code to process the response. If you use
|
|
* 'path' in your Ajax set-up, your route controller will be triggered with only
|
|
* the information you provide in the URL. If you use 'callback', your callback
|
|
* method is a function, which will receive the $form and $form_state from the
|
|
* triggering form. You can use $form_state to get information about the
|
|
* data the user has entered into the form. For instance, in the above example
|
|
* for the date format preview,
|
|
* \Drupal\config_translation\FormElement\DateFormat\ajaxSample() does this to
|
|
* get the format string entered by the user:
|
|
* @code
|
|
* $format_value = \Drupal\Component\Utility\NestedArray::getValue(
|
|
* $form_state->getValues(),
|
|
* $form_state->getTriggeringElement()['#array_parents']);
|
|
* @endcode
|
|
*
|
|
* Once you have processed the input, you have your choice of returning HTML
|
|
* markup or a set of Ajax commands. If you choose to return HTML markup, you
|
|
* can return it as a string or a renderable array, and it will be placed in
|
|
* the defined 'wrapper' element (see documentation above in @ref sub_form).
|
|
* In addition, any messages returned by
|
|
* \Drupal\Core\Messenger\Messenger::all(), themed as in
|
|
* status-messages.html.twig, will be prepended.
|
|
*
|
|
* To return commands, you need to set up an object of class
|
|
* \Drupal\Core\Ajax\AjaxResponse, and then use its addCommand() method to add
|
|
* individual commands to it. In the date format preview example, the format
|
|
* output is calculated, and then it is returned as replacement markup for a div
|
|
* like this:
|
|
* @code
|
|
* $response = new AjaxResponse();
|
|
* $response->addCommand(new ReplaceCommand(
|
|
* '#edit-date-format-suffix',
|
|
* '<small id="edit-date-format-suffix">' . $format . '</small>'));
|
|
* return $response;
|
|
* @endcode
|
|
*
|
|
* The individual commands that you can return implement interface
|
|
* \Drupal\Core\Ajax\CommandInterface. Available commands provide the ability
|
|
* to pop up alerts, manipulate text and markup in various ways, redirect
|
|
* to a new URL, and the generic \Drupal\Core\Ajax\InvokeCommand, which
|
|
* invokes an arbitrary jQuery command.
|
|
*
|
|
* As noted above, status messages are prepended automatically if you use the
|
|
* 'wrapper' method and return HTML markup. This is not the case if you return
|
|
* commands, but if you would like to show status messages, you can add
|
|
* @code
|
|
* array('#type' => 'status_messages')
|
|
* @endcode
|
|
* to a render array, use \Drupal::service('renderer')->render() to render it,
|
|
* and add a command to place the messages in an appropriate location.
|
|
*
|
|
* @section sec_other Other methods for triggering Ajax
|
|
* Here are some additional methods you can use to trigger Ajax responses in
|
|
* Drupal:
|
|
* - Add class 'use-ajax' to a link. The link will be loaded using an Ajax
|
|
* call. When using this method, the href of the link can contain '/nojs/' as
|
|
* part of the path. When the Ajax JavaScript processes the page, it will
|
|
* convert this to '/ajax/'. The server is then able to easily tell if this
|
|
* request was made through an actual Ajax request or in a degraded state, and
|
|
* respond appropriately.
|
|
* - Add class 'use-ajax-submit' to a submit button in a form. The form will
|
|
* then be submitted via Ajax to the path specified in the #action. Like the
|
|
* ajax-submit class on links, this path will have '/nojs/' replaced with
|
|
* '/ajax/' so that the submit handler can tell if the form was submitted in a
|
|
* degraded state or not.
|
|
* - Add property '#autocomplete_route_name' to a text field in a form. The
|
|
* route controller for this route must return an array of options for
|
|
* autocomplete, as a \Symfony\Component\HttpFoundation\JsonResponse object.
|
|
* See the @link menu Routing topic @endlink for more information about
|
|
* routing.
|
|
*/
|
|
|
|
/**
|
|
* @} End of "defgroup ajax".
|
|
*/
|
|
|
|
/**
|
|
* @defgroup service_tag Service Tags
|
|
* @{
|
|
* Service tags overview
|
|
*
|
|
* Some services have tags, which are defined in the service definition. Tags
|
|
* are used to define a group of related services, or to specify some aspect of
|
|
* how the service behaves. Typically, if you tag a service, your service class
|
|
* must also implement a corresponding interface. Some common examples:
|
|
* - access_check: Indicates a route access checking service; see the
|
|
* @link menu Menu and routing system topic @endlink for more information.
|
|
* - cache.bin: Indicates a cache bin service; see the
|
|
* @link cache Cache topic @endlink for more information.
|
|
* - event_subscriber: Indicates an event subscriber service. Event subscribers
|
|
* can be used for dynamic routing and route altering; see the
|
|
* @link menu Menu and routing system topic @endlink for more information.
|
|
* They can also be used for other purposes; see
|
|
* http://symfony.com/doc/current/cookbook/doctrine/event_listeners_subscribers.html
|
|
* for more information.
|
|
* - needs_destruction: Indicates that a destruct() method needs to be called
|
|
* at the end of a request to finalize operations, if this service was
|
|
* instantiated. Services should implement \Drupal\Core\DestructableInterface
|
|
* in this case.
|
|
* - context_provider: Indicates a block context provider, used for example
|
|
* by block conditions. It has to implement
|
|
* \Drupal\Core\Plugin\Context\ContextProviderInterface.
|
|
* - http_client_middleware: Indicates that the service provides a guzzle
|
|
* middleware, see
|
|
* https://guzzle.readthedocs.org/en/latest/handlers-and-middleware.html for
|
|
* more information.
|
|
*
|
|
* Creating a tag for a service does not do anything on its own, but tags
|
|
* can be discovered or queried in a compiler pass when the container is built,
|
|
* and a corresponding action can be taken. See
|
|
* \Drupal\Core\Render\MainContent\MainContentRenderersPass for an example of
|
|
* finding tagged services.
|
|
*
|
|
* See @link container Services and Dependency Injection Container @endlink for
|
|
* information on services and the dependency injection container.
|
|
*
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup events Events
|
|
* @{
|
|
* Overview of event dispatch and subscribing
|
|
*
|
|
* @section sec_intro Introduction and terminology
|
|
* Events allow different components of the system to interact and communicate
|
|
* with each other. One system component dispatches the event at an appropriate
|
|
* time; many events are dispatched by Drupal core and the Symfony event system
|
|
* in every request. Other system components can register as event subscribers;
|
|
* when an event is dispatched, a method is called on each registered
|
|
* subscriber, allowing each one to react. For more on the general concept of
|
|
* events, see
|
|
* http://symfony.com/doc/current/components/event_dispatcher/introduction.html
|
|
*
|
|
* @section sec_dispatch Dispatching events
|
|
* To dispatch an event, call the
|
|
* \Symfony\Contracts\EventDispatcher\EventDispatcherInterface::dispatch()
|
|
* method on the 'event_dispatcher' service (see the
|
|
* @link container Services topic @endlink for more information about how to
|
|
* interact with services). The first argument is the unique event name, which
|
|
* you should normally define as a constant in a separate static class (see
|
|
* \Symfony\Component\HttpKernel\KernelEvents and
|
|
* \Drupal\Core\Config\ConfigEvents for examples). The second argument is a
|
|
* \Drupal\Component\EventDispatcher\Event object; normally you will need to
|
|
* extend this class, so that your event class can provide data to the event
|
|
* subscribers.
|
|
*
|
|
* @section sec_subscribe Registering event subscribers
|
|
* Here are the steps to register an event subscriber:
|
|
* - Define a service in your module, tagged with 'event_subscriber' (see the
|
|
* @link container Services topic @endlink for instructions).
|
|
* - Define a class for your subscriber service that implements
|
|
* \Symfony\Component\EventDispatcher\EventSubscriberInterface
|
|
* - In your class, the getSubscribedEvents method returns a list of the events
|
|
* this class is subscribed to, and which methods on the class should be
|
|
* called for each one. Example:
|
|
* @code
|
|
* public static function getSubscribedEvents() {
|
|
* // Subscribe to kernel terminate with priority 100.
|
|
* $events[KernelEvents::TERMINATE][] = array('onTerminate', 100);
|
|
* // Subscribe to kernel request with default priority of 0.
|
|
* $events[KernelEvents::REQUEST][] = array('onRequest');
|
|
* return $events;
|
|
* }
|
|
* @endcode
|
|
* - Write the methods that respond to the events; each one receives the
|
|
* event object provided in the dispatch as its one argument. In the above
|
|
* example, you would need to write onTerminate() and onRequest() methods.
|
|
*
|
|
* Note that in your getSubscribedEvents() method, you can optionally set the
|
|
* priority of your event subscriber (see terminate example above). Event
|
|
* subscribers with higher priority numbers get executed first; the default
|
|
* priority is zero. If two event subscribers for the same event have the same
|
|
* priority, the one defined in a module with a lower module weight will fire
|
|
* first. Subscribers defined in the same services file are fired in
|
|
* definition order. If order matters defining a priority is strongly advised
|
|
* instead of relying on these two tie breaker rules as they might change in a
|
|
* minor release.
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @defgroup session Sessions
|
|
* @{
|
|
* Store and retrieve data associated with a user's browsing session.
|
|
*
|
|
* @section sec_intro Overview
|
|
* The Drupal session management subsystem is built on top of the Symfony
|
|
* session component. It is optimized in order to minimize the impact of
|
|
* anonymous sessions on caching proxies. A session is only started if necessary
|
|
* and the session cookie is removed from the browser as soon as the session
|
|
* has no data. For this reason it is important for contributed and custom
|
|
* code to remove session data if it is not used anymore.
|
|
*
|
|
* @section sec_usage Usage
|
|
* Session data is accessed via the
|
|
* \Symfony\Component\HttpFoundation\Request::getSession()
|
|
* method, which returns an instance of
|
|
* \Symfony\Component\HttpFoundation\Session\SessionInterface. The most
|
|
* important methods on SessionInterface are set(), get(), and remove().
|
|
*
|
|
* The following code fragment shows the implementation of a counter controller
|
|
* relying on the session:
|
|
* @code
|
|
* public function counter(Request $request) {
|
|
* $session = $request->getSession();
|
|
* $count = $session->get('mymodule.counter', 0) + 1;
|
|
* $session->set('mymodule.counter', $count);
|
|
*
|
|
* return [
|
|
* '#markup' => $this->t('Page Views: @count', ['@count' => $count]),
|
|
* '#cache' => [
|
|
* 'max-age' => 0,
|
|
* ],
|
|
* ];
|
|
* }
|
|
*
|
|
* public function reset(Request $request) {
|
|
* $session = $request->getSession();
|
|
* $session->remove('mymodule.counter');
|
|
* }
|
|
* @endcode
|
|
*
|
|
* It is important to keep the amount of data stored inside the session to a
|
|
* minimum, as the complete session is loaded on every request. Also third
|
|
* party session storage backends do not necessarily allow objects of unlimited
|
|
* size. If it is necessary to collect a non-trivial amount of data specific to
|
|
* a user's session, use the Key/Value store to save the serialized data and
|
|
* only store the key to the entry in the session.
|
|
*
|
|
* @section sec_reserved Reserved attributes and namespacing
|
|
* Contributed modules relying on the session are encouraged to namespace
|
|
* session attributes by prefixing them with their project name or an
|
|
* abbreviation thereof.
|
|
*
|
|
* Some attributes are reserved for Drupal core and must not be accessed from
|
|
* within contributed and custom code. Reserved attributes include:
|
|
* - uid: The user ID for an authenticated user. The value of this attribute
|
|
* cannot be modified.
|
|
*
|
|
* @section sec_custom_session_bags Custom session bags
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|
* Modules can register custom session bags in order to provide type safe
|
|
* interfaces on module specific session data. A session bag must implement
|
|
* \Symfony\Component\HttpFoundation\Session\SessionBagInterface. Custom session
|
|
* bags are registered using a service entry tagged with the session_bag service
|
|
* tag. Custom session bags can be accessed through the session retrieved from
|
|
* the request object.
|
|
*
|
|
* Example service definition:
|
|
* @code
|
|
* session_test.session_bag:
|
|
* class: Drupal\session_test\Session\TestSessionBag
|
|
* tags:
|
|
* - { name: session_bag }
|
|
* @endcode
|
|
*
|
|
* Example of accessing a custom session bag:
|
|
* @code
|
|
* $bag = $request->getSession()->getBag(TestSessionBag::BAG_NAME);
|
|
* $bag->setFlag();
|
|
* @endcode
|
|
* Session data must be deleted from custom session bags as soon as it is no
|
|
* longer needed (see @ref sec_intro above).
|
|
* @}
|
|
*/
|