web commit by joey

[git.ikiwiki.info.git] / doc / plugins / write.mdwn

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 0f2c2634476d0512421884b11fcc1ffae8f16e87..969862842a01eb07a97f877f705d2b5708af2f79 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -17,39 +17,93 @@ being edited.
 
 ## Registering plugins
 
 
 ## Registering plugins
 

-Plugins should, when imported, call IkiWiki::register_plugin to hook into
-ikiwiki. The function takes four parameters:
-
-1. A method type. Use "preprocess" to register a [[PreProcessorDirective]]
-2. A command name. This is the bit that will appear inside brackets in a
-   page.
-3. A reference to a subroutine that is run when the plugin is used.
+Plugins should, when imported, call IkiWiki::hook to hook into ikiwiki's
+processing. The function uses named parameters, and use varies depending on
+the type of plugin being registered. Note that a plugin can call the
+function more than once to register multiple hooks. All calls to
+IkiWiki::hook should be passed a "type" parameter, which gives the type of
+hook, a "id" paramter, which should be a unique string for this plugin, and
+a "call" parameter, which is a reference to a function to call for the
+hook.

 
 ## Writing a [[PreProcessorDirective]]
 
 
 ## Writing a [[PreProcessorDirective]]
 

-For preprocessor directives, the subroutine is passed named parameters. A
+This 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 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. All parameters included in the directive are included
 "page" parameter gives the name of the page that embedded the preprocessor directive. All parameters included in the directive are included

-as named parameters as well. Whatever the subroutine returns goes onto the
+as named parameters as well. Whatever the function returns goes onto the

 page in place of the directive.
 
 page in place of the directive.
 

-## Error handing in plugins
+### 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.
 
 
 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
+### Html issues

 
 Note that if [[HTMLSanitization]] 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 along with the rest of the page.
 
 
 Note that if [[HTMLSanitization]] 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 along with the rest of the page.
 

+## Other types of hooks
+
+Beyond PreProcessorDirectives, Other types of hooks that can be used by
+plugins include:
+
+### checkconfig
+
+       IkiWiki::hook(type => "checkconfig", id => "foo", call => \&checkconfig);
+
+This is useful if the plugin needs to check for, or modify ikiwiki's
+configuration. It's called early in the ikiwiki startup process. The
+function is passed no values. It's ok for the function to call
+IkiWiki::error if something isn't configured right.
+
+### filter
+
+       IkiWiki::hook(type => "filter", id => "foo", call => \&filter);
+
+Runs on the raw source of a page, before anything else touches it, and can
+make arbitrary changes. The function is passed named parameters `page` and
+`content` should return the filtered content.
+
+### delete
+
+       IkiWiki::hook(type => "delete", id => "foo", call => \&dele);
+
+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.
+
+### render
+
+       IkiWiki::hook(type => "render", id => "foo", call => \&render);
+
+Each time ikiwiki renders a change or addition (but not deletion) of a page
+to the wiki, the referenced function is called, and passed the name of the
+source file that was rendered.
+
+### cgi
+
+       IkiWiki::hook(type => "cgi", id => "foo", call => \&cgi);
+
+Use this to hook into ikiwiki's cgi script. Each registered cgi hook is
+called in turn, and passed a CGI object. The hook should examine the
+parameters, and if it will handle this CGI request, output a page and
+terminate the program.
+

 ## Wiki configuration
 
 ## 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
+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
 [[ikiwiki.setup]], which sets the hash content to configure the wiki.
 
 ## Wiki data


@@ -58,9 +112,9 @@ 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::links` lists the names of each page
 use the following hashes, using a page name as the key:
 
 * `%IkiWiki::links` lists the names of each page

-  that is linked to from that page in an array reference.
+  that a page links to, in an array reference.

 * `%IkiWiki::pagemtime` contains the last modification time of each page
 * `%IkiWiki::pagemtime` contains the last modification time of each page

-* `%IkiWiki::pagectime` contains the creation time of each page`
+* `%IkiWiki::pagectime` contains the creation time of each page

 * `%IkiWiki::renderedfiles` contains the name of the file rendered by a
   page
 * `%IkiWiki::pagesources` contains the name of the source file for a page.
 * `%IkiWiki::renderedfiles` contains the name of the file rendered by a
   page
 * `%IkiWiki::pagesources` contains the name of the source file for a page.


@@ -71,3 +125,27 @@ use the following hashes, using a page name as the key:
   Many plugins will need to add dependencies to this hash; the best way to do
   it is by using the IkiWiki::add_depends function, which takes as its
   parameters the page name and a [[GlobList]] of dependencies to add.
   Many plugins will need to add dependencies to this hash; the best way to do
   it is by using the IkiWiki::add_depends function, which takes as its
   parameters the page name and a [[GlobList]] of dependencies to add.

+
+## Page templates
+
+Plugins are mostly limited to changing the content of pages, to change the
+look and feel of the wiki it's generally better to use a stylesheet and
+[[templates]]. However, there are some hooks in the templates that plugins
+can use to add stuff to the wiki's UI:
+
+### Adding content to the page header
+
+Html that is added to $IkiWiki::config{headercontent} will show up in the
+header of the page. One good thing to put here is a search form.
+
+## RCS plugins
+
+ikiwiki's support for revision control systems also uses pluggable perl
+modules. These are in the `IkiWiki::RCS` namespace, for example
+`IkiWiki::RCS::svn`. 
+
+Each RCS plugin must support all the IkiWiki::rcs\_* functions.
+See IkiWiki::RCS::Stub for the full list of functions. It's ok if
+rcs\_getctime does nothing except for throwing an error.
+
+See [[about_RCS_backends]] for some more info.