* template: Remove bogus htmlize pass added in 2.16.

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

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 016746abb41ce5befff20b79433dc1bee45344ea..0da425402fb53b826eab803fb619e3daa8ed97c6 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -1,3 +1,12 @@
+Ikiwiki's plugin interface allows all kinds of useful [[plugins]] to be
+written to extend ikiwiki in many ways. Despite the length of this page,
+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]]
+
+## Types of plugins
+

 Most ikiwiki [[plugins]] are written in perl, like ikiwiki. This gives the
 plugin full access to ikiwiki's internals, and is the most efficient.
 However, plugins can actually be written in any language that supports XML
 Most ikiwiki [[plugins]] are written in perl, like ikiwiki. This gives the
 plugin full access to ikiwiki's internals, and is the most efficient.
 However, plugins can actually be written in any language that supports XML


@@ -22,8 +31,6 @@ they're the same as far as how they hook into ikiwiki. This document will
 explain how to write both sorts of plugins, albeit with an emphasis on perl
 plugins.
 
 explain how to write both sorts of plugins, albeit with an emphasis on perl
 plugins.
 

-[[toc levels=2]]
-

 ## Considerations
 
 One thing to keep in mind when writing a plugin is that ikiwiki is a wiki
 ## Considerations
 
 One thing to keep in mind when writing a plugin is that ikiwiki is a wiki


@@ -94,8 +101,8 @@ make arbitrary changes. The function is passed named parameters "page",
 
 ### preprocess
 
 
 ### preprocess
 

-Adding a [[PreProcessorDirective]] is probably the most common use of a
-plugin.
+Adding a [[ikiwiki/PreProcessorDirective]] is probably the most common use
+of a plugin.

 
         hook(type => "preprocess", id => "foo", call => \&preprocess);
 
 
         hook(type => "preprocess", id => "foo", call => \&preprocess);
 


@@ -116,14 +123,16 @@ An optional "scan" parameter, if set to a true value, makes the hook be
 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
 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
 
 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
-preprocessor time. Text output by a preprocessor directive will be
-linkified and passed through markdown (or whatever engine is used to htmlize
-the page) along with the rest of the page.
+[[ikiwiki/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 linkified and passed through markdown (or whatever engine is used to
+htmlize the page) along with the rest of the page.

 
 ### htmlize
 
 
 ### htmlize
 


@@ -141,7 +150,7 @@ return the htmlized content.
 
        hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);
 
 
        hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);
 

-[[Templates|wikitemplate]] are filled out for many different things in
+[[Templates|wikitemplates]] are filled out for many different things in

 ikiwiki, like generating a page, or part of a blog page, or an rss feed, or
 a cgi. This hook allows modifying the variables available on those
 templates. The function is passed named parameters. The "page" and
 ikiwiki, like generating a page, or part of a blog page, or an rss feed, or
 a cgi. This hook allows modifying the variables available on those
 templates. The function is passed named parameters. The "page" and


@@ -157,7 +166,7 @@ a new custom parameter to the template.
 
        hook(type => "templatefile", id => "foo", call => \&templatefile);
 
 
        hook(type => "templatefile", id => "foo", call => \&templatefile);
 

-This hook allows plugins to change the [[template|wikitemplate]] that is
+This hook allows plugins to change the [[template|wikitemplates]] that is

 used for a page in the wiki. The hook is passed a "page" parameter, and
 should return the name of the template file to use, or undef if it doesn't
 want to change the default ("page.tmpl"). Template files are looked for in
 used for a page in the wiki. The hook is passed a "page" parameter, and
 should return the name of the template file to use, or undef if it doesn't
 want to change the default ("page.tmpl"). Template files are looked for in


@@ -239,10 +248,27 @@ a page can be edited using the web interface (commits from revision control
 bypass it). When a page is edited, each registered canedit hook is called
 in turn, and passed the page name, a CGI object, and a session object.
 
 bypass it). When a page is edited, each registered canedit hook is called
 in turn, and passed the page name, a CGI object, and a session object.
 

-If edit can proceed, the hook should return "". If the edit is not allowed
-by this hook, the hook should return an error message for the user to see.

 If the hook has no opinion about whether the edit can proceed, return
 If the hook has no opinion about whether the edit can proceed, return

-`undef`, and the next plugin will be asked to decide.
+`undef`, and the next plugin will be asked to decide. If edit can proceed,
+the hook should return "". If the edit is not allowed by this hook, the
+hook should return an error message for the user to see, or a function 
+that can be run to log the user in or perform other action necessary for
+them to be able to edit the page.
+
+This hook should avoid directly redirecting the user to a signin page,
+since it's sometimes used to test to see which pages in a set of pages a
+user can edit.
+
+### editcontent
+
+       hook(type => "editcontent", id => "foo", call => \&editcontent);
+
+This hook is called when a page is saved (or previewed) using the web
+interface. It is passed named parameters: `content`, `page`, `cgi`, and
+`session`. These are, respectively, the new page content as entered by the
+user, the page name, a `CGI` object, and the user's `CGI::Session`. 
+
+It can modify the content as desired, and should return the content.

 
 ### formbuilder
 
 
 ### formbuilder
 


@@ -251,8 +277,9 @@ If the hook has no opinion about whether the edit can proceed, return
 
 These hooks allow tapping into the parts of ikiwiki that use [[cpan
 CGI::FormBuilder]] to generate web forms. These hooks are passed named
 
 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`, and `form`. These are, respectively, the
-`CGI` object, the user's `CGI::Session`, and a `CGI::FormBuilder`.
+parameters: `cgi`, `session`, `form`, and `buttons`. These are, respectively,
+the `CGI` object, the user's `CGI::Session`, a `CGI::FormBuilder`, and a
+reference to an array of names of buttons to go on the form.

 
 Each time a form is set up, the `formbuilder_setup` hook is called.
 Typically the `formbuilder_setup` hook will check the form's title, and if
 
 Each time a form is set up, the `formbuilder_setup` hook is called.
 Typically the `formbuilder_setup` hook will check the form's title, and if


@@ -260,11 +287,8 @@ it's a form that it needs to modify, will call various methods to
 add/remove/change fields, tweak the validation code for the fields, etc. It
 will not validate or display the form.
 
 add/remove/change fields, tweak the validation code for the fields, etc. It
 will not validate or display the form.
 

-Form validation and display can be overridden by the formbuilder hook.
-By default, ikiwiki will do a basic validation and display of the form,
-but if this hook is registered, it will stop that and let the hook take
-over. This hook is passed an additional named parameter: `buttons` is an
-array of the submit buttons for the form.
+Just before a form is displayed to the user, the `formbuilder` hook is
+called. It can be used to validate the form, but should not display it.

 
 ### savestate
 
 
 ### savestate
 


@@ -295,6 +319,23 @@ A plugin can access the wiki's configuration via the `%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.
 
 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.
 

+### %pagestate
+
+The `%pagestate` hash can be used by plugins to save state that they will need
+next time ikiwiki is run. The hash holds per-page state, so to set a value,
+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.
+
+When pages are deleted, ikiwiki automatically deletes their pagestate too.
+
+Note that page state does not persist across wiki rebuilds, only across
+wiki updates.
+

 ### Other variables
 
 If your plugin needs to access data about other pages in the wiki. It can
 ### Other variables
 
 If your plugin needs to access data about other pages in the wiki. It can


@@ -333,9 +374,10 @@ 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
 
 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 [[PreProcessorDirective]]
-is passed bad parameters, it's better to return an error message, which can
-appear on the wiki page, rather than calling error().
+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().

 
 #### `template($;@)`
 
 
 #### `template($;@)`
 


@@ -350,12 +392,12 @@ page created from it. (Ie, it appends ".html".)
 
 #### `add_depends($$)`
 
 
 #### `add_depends($$)`
 

-Makes the specified page depend on the specified [[PageSpec]].
+Makes the specified page depend on the specified [[ikiwiki/PageSpec]].

 
 #### `pagespec_match($$;@)`
 
 
 #### `pagespec_match($$;@)`
 

-Passed a page name, and [[PageSpec]], returns true if the [[PageSpec]]
-matches the page.
+Passed a page name, and [[ikiwiki/PageSpec]], returns true if the
+[[ikiwiki/PageSpec]] matches the page.

 
 Additional named parameters can be passed, to further limit the match.
 The most often used is "location", which specifies the location the
 
 Additional named parameters can be passed, to further limit the match.
 The most often used is "location", which specifies the location the


@@ -368,7 +410,7 @@ Given a page and the text of a link on the page, determine which
 existing page that link best points to. Prefers pages under a
 subdirectory with the same name as the source page, failing that
 goes down the directory tree to the base looking for matching
 existing page that link best points to. Prefers pages under a
 subdirectory with the same name as the source page, failing that
 goes down the directory tree to the base looking for matching

-pages, as described in [[SubPage/LinkingRules]].
+pages, as described in [[ikiwiki/SubPage/LinkingRules]].

 
 #### `htmllink($$$;@)`
 
 
 #### `htmllink($$$;@)`
 


@@ -394,7 +436,8 @@ control some options. These are:
 * forcesubpage  - set to force a link to a subpage
 * linktext - set to force the link text to something
 * anchor - set to make the link include an anchor
 * forcesubpage  - set to force a link to a subpage
 * linktext - set to force the link text to something
 * anchor - set to make the link include an anchor

-* rel - set to add a rel attribute to the link.
+* rel - set to add a rel attribute to the link
+* class - set to add a css class to the link

 
 #### `readfile($;$)`
 
 
 #### `readfile($;$)`
 


@@ -430,6 +473,10 @@ 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.
 

+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
+them. will_render also does a few important security checks.
+

 #### `pagetype($)`
 
 Given the name of a source file, returns the type of page it is, if it's
 #### `pagetype($)`
 
 Given the name of a source file, returns the type of page it is, if it's


@@ -443,13 +490,24 @@ that corresponds to that file.
 #### `srcfile($)`
 
 Given the name of a source file in the wiki, searches for the file in
 #### `srcfile($)`
 
 Given the name of a source file in the wiki, searches for the file in

-the source directory and the underlay directory, and returns the full
-path to the first file found.
+the source directory and the underlay directories (most recently added
+underlays first), and returns the full path to the first file found.
+
+#### `add_underlay($)`
+
+Adds a directory to the set of underlay directories that ikiwiki will
+search for files.

 
 

-#### `displaytime($)`
+If the directory name is not absolute, ikiwiki will assume it is in
+the parent directory of the configured underlaydir.
+
+#### `displaytime($;$)`

 
 Given a time, formats it for display.
 
 
 Given a time, formats it for display.
 

+The optional second parameter is a strftime format to use to format the
+time.
+

 #### `gettext`
 
 This is the standard gettext function, although slightly optimised.
 #### `gettext`
 
 This is the standard gettext function, although slightly optimised.


@@ -467,22 +525,22 @@ rendered to.
 
 ## RCS plugins
 
 
 ## RCS plugins
 

-ikiwiki's support for revision control systems also uses pluggable perl
-modules. These are in the `IkiWiki::RCS` namespace, for example
+ikiwiki's support for [[revision_control_systems|rcs]] 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.
 
 `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.
+See [[RCS_details|rcs/details]] for some more info.

 
 ## PageSpec plugins
 
 It's also possible to write plugins that add new functions to
 
 ## PageSpec plugins
 
 It's also possible to write plugins that add new functions to

-[[PageSpecs|PageSpec]]. Such a plugin should add a function to the
+[[PageSpecs|ikiwiki/PageSpec]]. Such a plugin should add a function to the

 IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is
 IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is

-how it will be accessed in a [[PageSpec]]. The function will be passed
+how it will be accessed in a [[ikiwiki/PageSpec]]. The function will be passed

 two parameters: The name of the page being matched, and the thing to match
 against. It may also be passed additional, named parameters. It should return
 a IkiWiki::SuccessReason object if the match succeeds, or an
 two parameters: The name of the page being matched, and the thing to match
 against. It may also be passed additional, named parameters. It should return
 a IkiWiki::SuccessReason object if the match succeeds, or an