X-Git-Url: https://scripts.mit.edu/gitweb/www/ikiwiki.git/blobdiff_plain/40d739cabadf0686fd6b6fb887540fc50cec6669..253c4a9acc4c1cde24a6c63aab88447dbc293756:/doc/plugins/write.mdwn

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index f9395eb5e..969862842 100644
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -17,38 +17,93 @@ being edited.
 
 ## 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 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.
+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]]
 
+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.
+Replace "foo" with the command name that will be used inside brackers for
+the preprocessor directive.
 
-Each time the directive is processed, the referenced subroutine (`preprocess` in the example above) is called, and is passed named parameters. A
+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
-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.
 
-## 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.
 
-## 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.
 
+## 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
 
-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
@@ -71,12 +126,26 @@ use the following hashes, using a page name as the key:
   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.
+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.
+rcs\_getctime does nothing except for throwing an error.
+
+See [[about_RCS_backends]] for some more info.