it's not really hard. This page is a complete reference to everything a
plugin might want to do. There is also a quick [[tutorial]].
-[[toc levels=2]]
+[[!toc levels=2]]
## Types of plugins
Plugins should, when imported, call `hook()` to hook into ikiwiki's
processing. The function uses named parameters, and use varies depending on
-the type of hook being registered -- see below. Note that a plugin can call
-the function more than once to register multiple hooks. All calls to
-`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 tells what function to call for the hook.
+the type of hook being registered -- see below. A plugin can call
+the function more than once to register multiple hooks.
+
+All calls to `hook()` should be passed a "type" parameter, which gives the
+type of hook, a "id" parameter, which should be a unique string for this
+plugin, and a "call" parameter, which tells what function to call for the
+hook.
An optional "last" parameter, if set to a true value, makes the hook run
after all other hooks of its type. Useful if the hook depends on some other
array of pages that will be rebuilt, and can modify the array, either
adding or removing files from it.
+### 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.
+
### filter
hook(type => "filter", id => "foo", call => \&filter);
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.
+"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`.
-
-The function is passed named parameters "page" and "content". Its return
-value is ignored.
-
### htmlize
hook(type => "htmlize", id => "ext", call => \&htmlize);
-Runs on the raw source of a page and turns it into html. The id parameter
+Runs on the source of a page and turns it into html. The id parameter
specifies the filename extension that a file must have to be htmlized using
this plugin. This is how you can add support for new and exciting markup
languages to ikiwiki.
a cgi. This hook allows modifying the variables available on those
templates. The function is passed named parameters. The "page" and
"destpage" parameters are the same as for a preprocess hook. The "template"
-parameter is a [[cpan HTML::Template]] object that is the template that
+parameter is a [[!cpan HTML::Template]] object that is the template that
will be used to generate the page. The function can manipulate that
template object.
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.
+
+### postscan
+
+ hook(type => "postscan", id => "foo", call => \&postscan);
+
+This hook is called once the full page body is available (but before the
+format hook). The most common use is to update search indexes. Added in
+ikiwiki 2.54.
+
+The function is passed named parameters "page" and "content". Its return
+value is ignored.
### 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.
hook(type => "auth", id => "foo", call => \&auth);
-This hook can be used to implement a different authentication method than
-the standard web form. When a user needs to be authenticated, each registered
-auth hook is called in turn, and passed a CGI object and a session object.
+This hook can be used to implement an authentication method. When a user
+needs to be authenticated, each registered auth hook is called in turn, and
+passed a CGI object and a session object.
If the hook is able to authenticate the user, it should set the session
object's "name" parameter to the authenticated user's name. Note that
hook(type => "formbuilder_setup", id => "foo", call => \&formbuilder_setup);
hook(type => "formbuilder", id => "foo", call => \&formbuilder);
-These hooks allow tapping into the parts of ikiwiki that use [[cpan
+These hooks allow tapping into the parts of ikiwiki that use [[!cpan
CGI::FormBuilder]] to generate web forms. These hooks are passed named
parameters: `cgi`, `session`, `form`, and `buttons`. These are, respectively,
the `CGI` object, the user's `CGI::Session`, a `CGI::FormBuilder`, and a
hook(type => "savestate", id => "foo", call => \&savestate);
-This hook is called wheneven ikiwiki normally saves its state, just before
+This hook is called whenever ikiwiki normally saves its state, just before
the state is saved. The function can save other state, modify values before
they're saved, etc.
To import the ikiwiki plugin interface:
- use IkiWiki '1.00';
+ use IkiWiki '2.00';
This will import several variables and functions into your plugin's
namespace. These variables and functions are the ones most plugins need,
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.
function that is called after the error message is printed, to do any final
cleanup.
-Note that while any plugin can use this for a fatal error, plugins should
-try to avoid dying on bad input, as that will halt the entire wiki build
-and make the wiki unusable. So for example, if a
-[[ikiwiki/PreProcessorDirective]] is passed bad parameters, it's better to
-return an error message, which can appear on the wiki page, rather than
-calling error().
+If called inside a preprocess hook, error() does not abort the entire
+wiki build, but instead replaces the [[ikiwiki/PreProcessorDirective]] with
+a version containing the error message.
+
+In other hooks, error() is a fatal error, so use with care. Try to avoid
+dying on bad input when building a page, as that will halt
+the entire wiki build and make the wiki unusable.
#### `template($;@)`
-Creates and returns a [[cpan HTML::Template]] object. The first parameter
+Creates and returns a [[!cpan HTML::Template]] object. The first parameter
is the name of the file in the template directory. The optional remaining
parameters are passed to `HTML::Template->new`.
Given the name of a source file, returns the name of the wiki page
that corresponds to that file.
-#### `srcfile($)`
+#### `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($)`
Adds a directory to the set of underlay directories that ikiwiki will
Passed a page and an extension, returns the filename that page will be
rendered to.
-## Internal use pages
+## Miscellaneous
+
+### Internal use pages
Sometimes it's useful to put pages in the wiki without the overhead of
having them be rendered to individual html files. Such internal use pages
PageSpecs glob patterns, but instead only by a special `internal()`
[[ikiwiki/PageSpec]].
-## RCS plugins
+### RCS plugins
ikiwiki's support for [[revision_control_systems|rcs]] also uses pluggable
perl modules. These are in the `IkiWiki::RCS` namespace, for example
See [[RCS_details|rcs/details]] for some more info.
-## PageSpec plugins
+### PageSpec plugins
It's also possible to write plugins that add new functions to
[[PageSpecs|ikiwiki/PageSpec]]. Such a plugin should add a function to the
against. It may also be passed additional, named parameters. It should return
a IkiWiki::SuccessReason object if the match succeeds, or an
IkiWiki::FailReason object if the match fails.
+
+### Setup plugins
+
+The ikiwiki setup file is loaded using a pluggable mechanism. If you
+look at the top of [[ikiwiki.setup]], it starts with
+'use IkiWiki::Setup::Standard', and the rest of the file is passed to
+that module's import method.
+
+It's possible to write other modules in the `IkiWiki::Setup::` namespace that
+can be used to configure ikiwiki in different ways. These modules should,
+when imported, populate `$IkiWiki::Setup::raw_setup` with a reference
+to a hash containing all the config items.
+
+By the way, to parse a ikiwiki setup file, a program just needs to
+do something like `use IkiWiki::Setup; my %setup=IkiWiki::Setup::load($filename)`