function is passed no values. It's ok for the function to call
`error()` if something isn't configured right.
+### refresh
+
+ hook(type => "refresh", id => "foo", call => \&refresh);
+
+This hook is called just before ikiwiki scans the wiki for changed files.
+It's useful for plugins that need to create or modify a source page. The
+function is passed no values.
+
### needsbuild
hook(type => "needsbuild", id => "foo", call => \&needsbuild);
-This allows a plugin the manipulate the list of files that need to be
+This allows a plugin to manipulate the list of files that need to be
built when the wiki is refreshed. The function is passed a reference to an
array of pages that will be rebuilt, and can modify the array, either
adding or removing files from it.
called during the preliminary scan that ikiwiki makes of updated pages,
before begining to render pages. This parameter should be set to true if
the hook modifies data in `%links`. Note that doing so will make the hook
-be run twice per page build, so avoid doing it for expensive hooks.
+be run twice per page build, so avoid doing it for expensive hooks. (As an
+optimisation, if your preprocessor hook is called in a void contets, you
+can assume it's being run in scan mode.)
Note that if the [[htmlscrubber]] is enabled, html in
[[ikiwiki/PreProcessorDirective]] output is sanitised, which may limit what
be linkified and passed through markdown (or whatever engine is used to
htmlize the page) along with the rest of the page.
+### linkify
+
+ hook(type => "linkify", id => "foo", call => \&linkify);
+
+This hook is called to convert [[WikiLinks|WikiLink]] on the page into html
+links. The function is passed named parameters "page", "destpage", and
+"content". It should return the linkified content. Present in IkiWiki 2.40
+and later.
+
+Plugins that implement linkify must also implement a scan hook, that scans
+for the links on the page and adds them to `%links`.
+
+### scan
+
+ hook(type => "scan", id => "foo", call => \&scan);
+
+This hook is called early in the process of building the wiki, and is used
+as a first pass scan of the page, to collect metadata about the page. It's
+mostly used to scan the page for WikiLinks, and add them to `%links`.
+Present in IkiWiki 2.40 and later.
+
+The function is passed named parameters "page" and "content". Its return
+value is ignored.
+
### htmlize
hook(type => "htmlize", id => "ext", call => \&htmlize);
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 named parameters: "page" and "content", and
-should return the sanitized content.
+The function is passed named parameters: "page", "destpage", and "content",
+and should return the sanitized content.
### format
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.
+header and footer inserted by ikiwiki, the html document type, etc. (It
+should not rely on always being passed the entire page, as it won't be
+when the page is being previewed.)
The function is passed named parameters: "page" and "content", and
should return the formatted content.
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 (including the http headers) and
-terminate the program.
+parameters, and if it will handle this CGI request, output a page
+(including the http headers) and terminate the program.
+
+Note that cgi hooks are called as early as possible, before any ikiwiki
+state is loaded, and with no session information.
### auth
use `%pagestate{$page}{$id}{$key}=$value`, and to retrieve the value,
use `%pagestate{$page}{$id}{$key}`.
-`$key` can be any string you like, but `$id` must be the same as the "id"
-parameter passed to `hook()` when registering the plugin. This is so
-ikiwiki can know when to delete pagestate for plugins that are no longer
-used.
+The `$value` can be anything that perl's Storable module is capable of
+serializing. `$key` can be any string you like, but `$id` must be the same
+as the "id" parameter passed to `hook()` when registering the plugin. This
+is so ikiwiki can know when to delete pagestate for plugins that are no
+longer used.
When pages are deleted, ikiwiki automatically deletes their pagestate too.
Given a page name and a destination file name (not including the base
destination directory), register that the page will result in that file
-being rendered. It's important to call this before writing to any file in
-the destination directory.
+being rendered.
+
+It's important to call this before writing to any file in the destination
+directory, and it's important to call it consistently every time, even if
+the file isn't really written this time -- unless you delete any old
+version of the file. In particular, in preview mode, this should still be
+called even if the file isn't going to be written to during the preview.
Ikiwiki uses this information to automatically clean up rendered files when
-the page that rendered them goes away or is changes to no longer render
+the page that rendered them goes away or is changed to no longer render
them. will_render also does a few important security checks.
#### `pagetype($)`
Given the name of a source file, returns the name of the wiki page
that corresponds to that file.
-#### `srcfile($)`
+#### `srcfile($;$)`
Given the name of a source file in the wiki, searches for the file in
the source directory and the underlay directories (most recently added
underlays first), and returns the full path to the first file found.
+Normally srcfile will fail with an error message if the source file cannot
+be found. The second parameter can be set to a true value to make it return
+undef instead.
+
#### `add_underlay($)`
Adds a directory to the set of underlay directories that ikiwiki will
Passed a page and an extension, returns the filename that page will be
rendered to.
+## Internal use pages
+
+Sometimes it's useful to put pages in the wiki without the overhead of
+having them be rendered to individual html files. Such internal use pages
+are collected together to form the RecentChanges page, for example.
+
+To make an internal use page, register a filename extension that starts
+with "_". Internal use pages cannot be edited with the web interface,
+generally shouldn't contain wikilinks or preprocessor directives (use
+either on them with extreme caution), and are not matched by regular
+PageSpecs glob patterns, but instead only by a special `internal()`
+[[ikiwiki/PageSpec]].
+
## RCS plugins
ikiwiki's support for [[revision_control_systems|rcs]] also uses pluggable