parallaxis/node_modules/express/lib/router/index.js

453 lines
10 KiB
JavaScript
Executable File

/**
* Module dependencies.
*/
var Route = require('./route');
var Layer = require('./layer');
var methods = require('methods');
var debug = require('debug')('express:router');
var parseUrl = require('parseurl');
var slice = Array.prototype.slice;
/**
* Initialize a new `Router` with the given `options`.
*
* @param {Object} options
* @return {Router} which is an callable function
* @api public
*/
var proto = module.exports = function(options) {
options = options || {};
function router(req, res, next) {
router.handle(req, res, next);
}
// mixin Router class functions
router.__proto__ = proto;
router.params = {};
router._params = [];
router.caseSensitive = options.caseSensitive;
router.strict = options.strict;
router.stack = [];
return router;
};
/**
* Map the given param placeholder `name`(s) to the given callback.
*
* Parameter mapping is used to provide pre-conditions to routes
* which use normalized placeholders. For example a _:user_id_ parameter
* could automatically load a user's information from the database without
* any additional code,
*
* The callback uses the same signature as middleware, the only difference
* being that the value of the placeholder is passed, in this case the _id_
* of the user. Once the `next()` function is invoked, just like middleware
* it will continue on to execute the route, or subsequent parameter functions.
*
* Just like in middleware, you must either respond to the request or call next
* to avoid stalling the request.
*
* app.param('user_id', function(req, res, next, id){
* User.find(id, function(err, user){
* if (err) {
* return next(err);
* } else if (!user) {
* return next(new Error('failed to load user'));
* }
* req.user = user;
* next();
* });
* });
*
* @param {String} name
* @param {Function} fn
* @return {app} for chaining
* @api public
*/
proto.param = function(name, fn){
// param logic
if ('function' == typeof name) {
this._params.push(name);
return;
}
// apply param functions
var params = this._params;
var len = params.length;
var ret;
if (name[0] === ':') {
name = name.substr(1);
}
for (var i = 0; i < len; ++i) {
if (ret = params[i](name, fn)) {
fn = ret;
}
}
// ensure we end up with a
// middleware function
if ('function' != typeof fn) {
throw new Error('invalid param() call for ' + name + ', got ' + fn);
}
(this.params[name] = this.params[name] || []).push(fn);
return this;
};
/**
* Dispatch a req, res into the router.
*
* @api private
*/
proto.handle = function(req, res, done) {
var self = this;
debug('dispatching %s %s', req.method, req.url);
var method = req.method.toLowerCase();
var search = 1 + req.url.indexOf('?');
var pathlength = search ? search - 1 : req.url.length;
var fqdn = 1 + req.url.substr(0, pathlength).indexOf('://');
var protohost = fqdn ? req.url.substr(0, req.url.indexOf('/', 2 + fqdn)) : '';
var idx = 0;
var removed = '';
var slashAdded = false;
var paramcalled = {};
// store options for OPTIONS request
// only used if OPTIONS request
var options = [];
// middleware and routes
var stack = self.stack;
// manage inter-router variables
var parent = req.next;
var parentUrl = req.baseUrl || '';
done = wrap(done, function(old, err) {
req.baseUrl = parentUrl;
req.next = parent;
old(err);
});
req.next = next;
// for options requests, respond with a default if nothing else responds
if (method === 'options') {
done = wrap(done, function(old, err) {
if (err || options.length === 0) return old(err);
var body = options.join(',');
return res.set('Allow', body).send(body);
});
}
next();
function next(err) {
if (err === 'route') {
err = undefined;
}
var layer = stack[idx++];
var layerPath;
if (!layer) {
return done(err);
}
if (slashAdded) {
req.url = req.url.substr(1);
slashAdded = false;
}
req.baseUrl = parentUrl;
req.url = protohost + removed + req.url.substr(protohost.length);
req.originalUrl = req.originalUrl || req.url;
removed = '';
try {
var path = parseUrl(req).pathname;
if (undefined == path) path = '/';
if (!layer.match(path)) return next(err);
// route object and not middleware
var route = layer.route;
// if final route, then we support options
if (route) {
// we don't run any routes with error first
if (err) {
return next(err);
}
req.route = route;
// we can now dispatch to the route
if (method === 'options' && !route.methods['options']) {
options.push.apply(options, route._options());
}
}
// Capture one-time layer values
req.params = layer.params;
layerPath = layer.path;
// this should be done for the layer
return self.process_params(layer, paramcalled, req, res, function(err) {
if (err) {
return next(err);
}
if (route) {
return layer.handle(req, res, next);
}
trim_prefix();
});
} catch (err) {
next(err);
}
function trim_prefix() {
var c = path[layerPath.length];
if (c && '/' != c && '.' != c) return next(err);
// Trim off the part of the url that matches the route
// middleware (.use stuff) needs to have the path stripped
removed = layerPath;
if (removed.length) {
debug('trim prefix (%s) from url %s', layerPath, req.url);
req.url = protohost + req.url.substr(protohost.length + removed.length);
}
// Ensure leading slash
if (!fqdn && req.url[0] !== '/') {
req.url = '/' + req.url;
slashAdded = true;
}
// Setup base URL (no trailing slash)
if (removed.length && removed.substr(-1) === '/') {
req.baseUrl = parentUrl + removed.substring(0, removed.length - 1);
} else {
req.baseUrl = parentUrl + removed;
}
debug('%s %s : %s', layer.handle.name || 'anonymous', layerPath, req.originalUrl);
var arity = layer.handle.length;
try {
if (err && arity === 4) {
layer.handle(err, req, res, next);
} else if (!err && arity < 4) {
layer.handle(req, res, next);
} else {
next(err);
}
} catch (err) {
next(err);
}
}
}
function wrap(old, fn) {
return function () {
var args = [old].concat(slice.call(arguments));
fn.apply(this, args);
};
}
};
/**
* Process any parameters for the layer.
*
* @api private
*/
proto.process_params = function(layer, called, req, res, done) {
var params = this.params;
// captured parameters from the layer, keys and values
var keys = layer.keys;
// fast track
if (!keys || keys.length === 0) {
return done();
}
var i = 0;
var name;
var paramIndex = 0;
var key;
var paramVal;
var paramCallbacks;
var paramCalled;
// process params in order
// param callbacks can be async
function param(err) {
if (err) {
return done(err);
}
if (i >= keys.length ) {
return done();
}
paramIndex = 0;
key = keys[i++];
if (!key) {
return done();
}
name = key.name;
paramVal = req.params[name];
paramCallbacks = params[name];
paramCalled = called[name];
if (paramVal === undefined || !paramCallbacks) {
return param();
}
// param previously called with same value or error occurred
if (paramCalled && (paramCalled.error || paramCalled.match === paramVal)) {
// restore value
req.params[name] = paramCalled.value;
// next param
return param(paramCalled.error);
}
called[name] = paramCalled = {
error: null,
match: paramVal,
value: paramVal
};
try {
return paramCallback();
} catch (err) {
return done(err);
}
}
// single param callbacks
function paramCallback(err) {
var fn = paramCallbacks[paramIndex++];
// store updated value
paramCalled.value = req.params[key.name];
if (err) {
// store error
paramCalled.error = err;
param(err);
return;
}
if (!fn) return param();
fn(req, res, paramCallback, paramVal, key.name);
}
param();
};
/**
* Use the given middleware function, with optional path, defaulting to "/".
*
* Use (like `.all`) will run for any http METHOD, but it will not add
* handlers for those methods so OPTIONS requests will not consider `.use`
* functions even if they could respond.
*
* The other difference is that _route_ path is stripped and not visible
* to the handler function. The main effect of this feature is that mounted
* handlers can operate without any code changes regardless of the "prefix"
* pathname.
*
* @param {String|Function} route
* @param {Function} fn
* @return {app} for chaining
* @api public
*/
proto.use = function(route, fn){
// default route to '/'
if ('string' != typeof route) {
fn = route;
route = '/';
}
if (typeof fn !== 'function') {
var type = {}.toString.call(fn);
var msg = 'Router.use() requires callback functions but got a ' + type;
throw new Error(msg);
}
// strip trailing slash
if ('/' == route[route.length - 1]) {
route = route.slice(0, -1);
}
var layer = new Layer(route, {
sensitive: this.caseSensitive,
strict: this.strict,
end: false
}, fn);
// add the middleware
debug('use %s %s', route || '/', fn.name || 'anonymous');
this.stack.push(layer);
return this;
};
/**
* Create a new Route for the given path.
*
* Each route contains a separate middleware stack and VERB handlers.
*
* See the Route api documentation for details on adding handlers
* and middleware to routes.
*
* @param {String} path
* @return {Route}
* @api public
*/
proto.route = function(path){
var route = new Route(path);
var layer = new Layer(path, {
sensitive: this.caseSensitive,
strict: this.strict,
end: true
}, route.dispatch.bind(route));
layer.route = route;
this.stack.push(layer);
return route;
};
// create Router#VERB functions
methods.concat('all').forEach(function(method){
proto[method] = function(path){
var route = this.route(path)
route[method].apply(route, [].slice.call(arguments, 1));
return this;
};
});