`IkiWiki::Plugin::skeleton` that can be fleshed out to make a useful
plugin. `IkiWiki::Plugin::pagecount` is another simple example.
-# Note
+[[toc levels=2]]
+
+## Considerations
One thing to keep in mind when writing a plugin is that ikiwiki is a wiki
*compiler*. So plugins influence pages when they are built, not when they
change until ikiwiki rebuilds the page for some other reason, like the page
being edited.
-# Registering plugins
+## Registering plugins
Plugins should, when imported, call IkiWiki::hook to hook into ikiwiki's
processing. The function uses named parameters, and use varies depending on
a "call" parameter, which is a reference to a function to call for the
hook.
-# Writing a [[PreProcessorDirective]]
-
-This is probably the most common use of a plugin.
-
- IkiWiki::hook(type => "preprocess", id => "foo", call => \&preprocess);
+## Types of hooks
-Replace "foo" with the command name that will be used inside brackers for
-the preprocessor directive.
-
-Each time the directive is processed, the referenced function (`preprocess`
-in the example above) is called, and is passed named parameters. A "page"
-parameter gives the name of the page that embedded the preprocessor
-directive, while a "destpage" parameter gices the name of the page the
-content is going to (different for inlined pages). All parameters included
-in the directive are included as named parameters as well. Whatever the
-function returns goes onto the page in place of the directive.
+In roughly the order they are called.
-## Error handing
-
-While a plugin can call ikiwiki's error routine for a fatal error, for
-errors that aren't intended to halt the entire wiki build, including bad
-parameters passed to a [[PreProcessorDirective]], etc, it's better to just
-return the error message as the output of the plugin.
-
-## Html issues
-
-Note that if the [[htmlscrubber]] is enabled, html in
-[[PreProcessorDirective]] output is sanitised, which may limit what your
-plugin can do. Also, the rest of the page content is not in html format at
-preprocessor time. Text output by a preprocessor directive will be passed
-through markdown (or whatever engine is used to htmlize the page) along
-with the rest of the page.
-
-# Other types of hooks
-
-Beyond PreProcessorDirectives, Other types of hooks that can be used by
-plugins include:
-
-## getopt
+### getopt
IkiWiki::hook(type => "getopt", id => "foo", call => \&getopt);
an option it cannot process, and should just skip over those options and
leave them in @ARGV.
-## checkconfig
+### checkconfig
IkiWiki::hook(type => "checkconfig", id => "foo", call => \&checkconfig);
function is passed no values. It's ok for the function to call
IkiWiki::error if something isn't configured right.
-## filter
+### filter
IkiWiki::hook(type => "filter", id => "foo", call => \&filter);
make arbitrary changes. The function is passed named parameters `page` and
`content` and should return the filtered content.
-## htmlize
+### preprocess
+
+Adding a [[PreProcessorDirective]] is probably the most common use of a
+plugin.
+
+ IkiWiki::hook(type => "preprocess", id => "foo", call => \&preprocess);
+
+Replace "foo" with the command name that will be used inside brackets for
+the preprocessor directive.
+
+Each time the directive is processed, the referenced function (`preprocess`
+in the example above) is called, and is passed named parameters. A "page"
+parameter gives the name of the page that embedded the preprocessor
+directive, while a "destpage" parameter gices the name of the page the
+content is going to (different for inlined pages). All parameters included
+in the directive are included as named parameters as well. Whatever the
+function returns goes onto the page in place of the directive.
+
+Note that if the [[htmlscrubber]] is enabled, html in
+[[PreProcessorDirective]] output is sanitised, which may limit what your
+plugin can do. Also, the rest of the page content is not in html format at
+preprocessor time. Text output by a preprocessor directive will be
+linkified and passed through markdown (or whatever engine is used to htmlize
+the page) along with the rest of the page.
+
+### htmlize
IkiWiki::hook(type => "htmlize", id => "ext", call => \&htmlize);
this plugin. This is how you can add support for new and exciting markup
languages to ikiwiki.
-## pagetemplate
+The function is passed named parameters: "page" and "content" and should
+return the htmlized content.
+
+### pagetemplate
IkiWiki::hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);
The most common thing to do is probably to call $template->param() to add
a new custom parameter to the template.
-## sanitize
+### sanitize
IkiWiki::hook(type => "sanitize", id => "foo", call => \&sanitize);
Use this to implement html sanitization or anything else that needs to
modify the body of a page after it has been fully converted to html.
-The function is passed the page content and should return the sanitized
-content.
-## format
+The function is passed named parameters: "page" and "content", and
+should return the sanitized content.
+
+### format
IkiWiki::hook(type => "format", id => "foo", call => \&format);
-The function is passed the complete page content and can reformat it
-and return the new content. The difference between format and sanitize is
-that sanitize only acts on the page body, while format can modify the
-entire html page including the header and footer inserted by ikiwiki, the
-html document type, etc.
+The difference between format and sanitize is that sanitize only acts on
+the page body, while format can modify the entire html page including the
+header and footer inserted by ikiwiki, the html document type, etc.
+
+The function is passed named parameters: "page" and "content", and
+should return the formatted content.
-## delete
+### delete
IkiWiki::hook(type => "delete", id => "foo", call => \&delete);
Each time a page or pages is removed from the wiki, the referenced function
is called, and passed the names of the source files that were removed.
-## change
+### change
IkiWiki::hook(type => "change", id => "foo", call => \&render);
wiki, the referenced function is called, and passed the names of the
source files that were rendered.
-## cgi
+### cgi
IkiWiki::hook(type => "cgi", id => "foo", call => \&cgi);
parameters, and if it will handle this CGI request, output a page and
terminate the program.
-## savestate
+### savestate
IkiWiki::hook(type => "savestate", id => "foo", call => \&savestate);
the state is saved. The function can save other state, modify values before
they're saved, etc.
-# Wiki configuration
+## Error handing
+
+While a plugin can call ikiwiki's `error` routine for a fatal error, for
+errors that aren't intended to halt the entire wiki build, including bad
+parameters passed to a [[PreProcessorDirective]], etc, it's better to just
+return the error message as the output of the plugin.
+
+## Wiki configuration
A plugin can access the wiki's configuration via the `%IkiWiki::config`
hash. The best way to understand the contents of the hash is to look at
[[ikiwiki.setup]], which sets the hash content to configure the wiki.
-# Wiki data
+## Wiki data
If your plugin needs to access data about other pages in the wiki. It can
use the following hashes, using a page name as the key:
* `%IkiWiki::forcerebuild` any pages set as the keys to this hash will be
treated as if they're modified and rebuilt.
-# A note on generating html links
+## Generating html links
Many plugins need to generate html links and add them to a page. This is
done by using the `IkiWiki::htmllink` function. The usual way to call
of the hook functions above; the ones that are not passed it are not used
during inlining and don't need to worry about this issue.
-# RCS plugins
+## RCS plugins
ikiwiki's support for revision control systems also uses pluggable perl
modules. These are in the `IkiWiki::RCS` namespace, for example