[[!meta author="spalax"]]
[[!template id=plugin name=compile author="[[Louis|spalax]]"]]

# Compile

The compile plugin provides the `compile` directive, used to on-the-fly compile
and publish documents.

For instance, if you want to publish files together with their sources (like
`.tex` and `.pdf` files), you can have the `.tex` file in your source wiki
directory, and command `\[[!compile files="foo.tex"]]` (or wikilink
`\[[foo.tex]]`, if the right option is set) will compile file and render as a
link to the `.pdf` file.

[[!toc startlevel=2]]

## Warning

Some important security notice.

- This plugins allows user to execute arbitrary commands when compiling the
  wiki.  Use at your own risk. If you use Ikiwiki as a static web site compiler
  (and not a wiki), and you are the only one to compile the wiki, there is no
  risk. If you *do* allow untrusted users to edit or comment on the wiki, they
  can use the `compile` directives to execute completely arbitrary code, regardless
  of configuration safeguards you may put.

- Source files are published, wheter option `source` is true or not. If
  `source` is false, source may not be *advertised*, but it is still available
  somewhere on your website (most likely by replacing in the compiled file URL
  the extension of the compiled file by the extension of the source file). So,
  do not use this plugin if you do not want to publish your source files
    (sorry: I designed this plugin to publish free stuff).

The plugin could be modified to only allow commands to be modified from the
configuration and it would be safer to use. However, it would still be vulnerable
to command injection attacks because it uses `qx()` command expansion, which
runs commands through `/bin/sh -c`. A thorough security review would be in order
before this should be considered secure running on untrusted input.

A simpler implementation, that only runs a predefined set of commands, may be
simpler to implement than auditing this whole plugin. For example, the
[[bibtex2html]] module performs a similar task than the compile module, but
hardcodes the command used and doesn't call it with `/bin/sh -c`. It could be
expanded to cover more commands. See this
[[plugins/contrib/bibtex2html/discussion/]] for a followup on this idea.

## Rationale

I want to publish some latex files, both source (`.tex`) and compiled (`.pdf`)
version, but I do not want to maintain two versions of the same file.

Using this plugin, I only have to maintain the `.tex` files, and thoses files
are compiled on the fly, so that the `pdf` is published.

## String formatting

Strings (destination name, template name and build command) accept python-like
syntax ``%{name}s``, which is replaced by the value of variable ``name``. The
following variables are abailable.

- `srcname`: Source name.
- `srcextension`: Extension of the source name.
- `filetype`: File type (extension of the source name, otherwise specified by directive).
- `dirname`: Directory of the source file.
- `wikiname`: Name of source file, relative to source wiki directory.
- `srcfullname`: Name of source file, relative to file system root.
- `basename`: Source name, without directory nor extension.
- `destname`: Destination name (without directory).
- `destextension`: Extension of the destination name.
- `targetname`: Destination name, relative to the destination directory.
- `destfullname`: Destination name, relative to file system root.

## Directive

### Usage

Basic usage of this plugin is:

    \[[!compile files="foo.ext"]]

It renders file `foo.ext` according to rules defined in the setup file, and
publish the compiled version.

### Arguments

All the arguments (but `source` and `filetype`) are string which are processed
using python-like string formatting, and described in the setup options section.

- `files`: List of files used in compilation, as space separated string. For
  instance, to compile some tex file including a png image, you will have:
  `files="foo.tex image.png"`. It is not possible to have filenames containing
  spaces (unless you provide me a patch to recognize escaped spaces).
- `filetype`: By default, the source file extension is used to determine build
  command and other configuration. If the same extension refer to different
  type of files, you can enforce the filetype using this argument. For
  instance, if some your LaTeX files have to be compiled with `pdflatex`, while
  the other require `latex`, your `compile_filetypes` can contains two keys
  `tex` and `texdvi`. By default, LaTeX files will be compiled using
  configuration associated to `tex`, unless directive has argument
  `filetype=texdvi`, in which case the latter configuration is used.
- `destname`: Name of the compiled file name.
- `build`: Build command.
- `source`: Boolean to choose whether to publish source file or not. The only
  effect is the template choice: source is always published (but not always
  advertised).
- `template`: Name of the template to use (if set, the `source` option is
  irrelevant).
- `var_*`: Any argument with a name starting with ``var_`` is transmitted to the command and template. For instance, if directive has argument ``var_foo=bar``, then string ``%{foo}s`` in the command will be replaced by ``bar``, and the template will have a variable named ``foo``, and ``<TMPL_VAR FOO>`` will be replaced by ``bar``.

### Extensions

Note: This directive does not work if source file name does not have an
extension (i.e. does not contain a dot). This should not be too hard to
implement, but I do not need it. Patches welcome.

## Configuration

Here are the setup options (most of them can be overloaded on a per-extension
basis by setup option `compile_filetypes`, or by directive arguments):

- `compile_source` (boolean): should sources be published with compiled file
  (this only affect template choice; see warning)? Default is true.
- `compile_template_source` (string): name of the template to use for compiled
  files when option `source` is true. Default is `compile_source.tmpl`.
- `compile_template_nosource` (string): name of the template to use for
  compiled files when option `source` is false. Default is
  `compile_nosource.tmpl`.
- `compile_filetypes` (string): Per extension configuration (see paragraph
  below).
- `compile_tmpdir` (string): Path of a directory to use to compile files:
  source file (and dependency) are copied to this directory before being
  compiled (to avoid messing the ikiwiki directory with compiled version or
  auxiliary files). Default is `SOURCE_WIKI/.ikwiki/tmp/compile`.
- `compile_bindir` (string): Directory containing binaries to use to compile
  files. Default is undefined.
- `compile_depends` (string): List of files all compiled files will depend on
  (see *Compilation* section below).
- `compile_build` (string): Command to use to compile files. Default
  is undefined.
- `compile_inline` (boolean): If true, wikilinks pointing to files with an
  extension specified in `compile_filetypes` are treated as a directive
  \[[!compile files="LINK"]]. For instance, if this is set globally (or just
  for tex), a wikilink \[[foo.tex]] will compile file `foo.tex`, and publish
  the compiled `foo.pdf` file.

### The `compile_filetypes` option

This variable is a json string, representing a dictionary. Keys are source file
extensions, values are dictionary of options applying only to files with this
extension.

Keys of these new directory are `source`, `template_nosource`,
`template_source`, `build`, `depends`, `inline`, and overrides generic options
defined above. They are themselves overriden by directive arguments (excepted
`inline`).

Example:

    compile_filetypes => '{
      "tex": {
        "build": "pdflatex %{basename}s",
        "destname": "%{basename}s.pdf",
        "depends": ["logo.png"],
        "inline": "1"
      },
      "texdvi": {
        "build": "latex %{basename}s",
        "destname": "%{basename}s.pdf",
        "depends": ["logo.eps"]
      }
    }'

## Compilation

### Dependencies

Before compilation, the source file and all dependencies are copied to the
temporary directory defined by option `compile_tmpdir`. For instance, if all
you LaTeX files are compiled using a custom class `foo.sty`, and a particular
file `bar.tex` uses the `logo.png` file, your setup option will contain
`foo.sty` as `depends`, and `compile` directive will be called using
`\[[!compile files="bar.tex logo.png"]]`. Then, before compilation, files
`foo.sty`, `bar.tex` and `logo.png` will be copied in the same temporary
directory.

Note that path are *flattened* when copied: before performing compilation of
directive `\[[!compile files="sub1/foo sub2/bar"]]`, files `foo` and `bar` will
be copied in the same directory: this temporary directory will contain failes
`foo` and `bar`, but not `sub1/foo` and `sub2/bar`.

### Build command

The build command used is (if defined, by priority order):

- defined by argument `build` of directive;
- setup command ``compile_filetypes{TYPE}{build}``;
- setup command ``compile_build`` (if you have a generic build command);
- command ``$config{compile_bindir}/${extension}s %{srcname}s`` (if setup variable ``compile_bindir``is defined, is a directory, and contains an executable file matching the extension, it will be used);
- command ``make -f $config{compile_bindir}/make.${extension}s %{destname}s`` (if setup variable ``compile_bindir`` is defined, is a directory, and contains a readable makefile ``make.EXTENSION``, it will be used).

## Template

The way links are rendered is defined in a template, which is (by order of
priority, some of them depends on whether ``source`` is true):

- argument `template` of directive;
- setup variable ``compile_filetypes{TYPE}{template_source}`` or ``compile_filetypes{TYPE}{template_nosource}``;
- setup variable ``compile_source`` or ``compile_nosource``;
- `compile_source.mdwn` or `compile_nosource.mdwn`.

It is passed the following variables:

- `DESTURL`: URL to the compiled file.
- `DESTNAME`: Name of the compiled file.
- `SRCURL`: URL to the source file.
- `SRCNAME`: Name of the source file (without directory).
- `ORIGNAME`: Name of the source file (with directory).

Note that templates can be used to display images (instead of a link to them).
For instance, if you have a `.tiff` file you want to convert to png before
displaying it on your website, you can use as a template:

    <img src="<TMPL_VAR DESTURL>">

# Download

Code and documentation can be found here : [[https://spalax.frama.io/gresille-ikiwiki/compile]].