meta headers are not sanitised; prevent html leaking into them

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

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index e09ca35104303cb0afdf326f2406d8f9317413cd..515c4d90d6091766a90b01a498507bd47bf99f4a 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -4,7 +4,7 @@ lowercase, such as `IkiWiki::Plugin::inline`. Ikiwiki includes a
 `IkiWiki::Plugin::skeleton` that can be fleshed out to make a useful
 plugin. `IkiWiki::Plugin::pagecount` is another simple example.
 
 `IkiWiki::Plugin::skeleton` that can be fleshed out to make a useful
 plugin. `IkiWiki::Plugin::pagecount` is another simple example.
 

-## Note
+# Note

 
 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
 
 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


@@ -15,25 +15,34 @@ random or changing thing on a page will generate a static page that won't
 change until ikiwiki rebuilds the page for some other reason, like the page
 being edited.
 
 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::register_plugin to hook into
-ikiwiki. The function takes four parameters:
+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.

 
 

-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.
+# Writing a [[PreProcessorDirective]]

 
 

-## Writing a [[PreProcessorDirective]]
+This is probably the most common use of a plugin.

 
 

-For preprocessor commands, the subroutine is passed named parameters. A
-"page" parameter gives the name of the page that embedded the preprocessor
-command. All parameters included in the preprocessor command are included
-as named parameters as well. Whatever the subroutine returns goes onto the
-page in place of the command.
+        IkiWiki::hook(type => "preprocess", id => "foo", call => \&preprocess);

 
 

-## Error handing in plugins
+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 as named
+parameters as well. Whatever the function returns goes onto the page in
+place of the directive.
+
+## 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
 
 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


@@ -42,26 +51,93 @@ return the error message as the output of the plugin.
 
 ## Html issues
 
 
 ## Html issues
 

-Note that if [[HTMLSanitization]] is enabled, html in 
+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
 [[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.
+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` and should return the filtered content.
+
+## pagetemplate
+
+       IkiWiki::hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);
+
+Each time a page is rendered, a [[template|templates]] is filled out.
+This hook allows modifying that template. The function is passed the name
+of the page, and a `HTML::Template` object that is the template that will
+be used to generate the page. It can manipulate that template, the most
+common thing to do is probably to call $template->param() to add a new
+custom parameter to the template.
+
+## sanitize
+
+       IkiWiki::hook(type => "sanitize", id => "foo", call => \&sanitize);

 
 

-## Wiki configuration
+Use this to implement html sanitization or anything else that needs to
+modify the content of a page after it has been fully converted to html.
+The function is passed the page content and should return the sanitized
+content.

 
 

-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
+## 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.
+
+## change
+
+       IkiWiki::hook(type => "change", id => "foo", call => \&render);
+
+Each time ikiwiki renders a change or addition (but not deletion) to the
+wiki, the referenced function is called, and passed the names of the
+source files that were 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

 [[ikiwiki.setup]], which sets the hash content to configure the wiki.
 
 [[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::links` lists the names of each page
 
 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

-  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.


@@ -72,3 +148,15 @@ 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.

+
+# 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.