X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/e49ff966a39d1037ccbf168b8dbd12618cf1b41e..aa2b3b8f637d0f3abe2ebf3845a22781ffd83c72:/doc/plugins/write.mdwn diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn index 925717777..dd0ab451f 100644 --- a/doc/plugins/write.mdwn +++ b/doc/plugins/write.mdwn @@ -4,7 +4,9 @@ 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. -# Note +[[toc levels=2]] + +## Considerations 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 @@ -15,7 +17,7 @@ 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. -# Registering plugins +## 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 @@ -26,45 +28,11 @@ 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. +## Types of hooks - IkiWiki::hook(type => "preprocess", id => "foo", call => \&preprocess); +In roughly the order they are called. -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, while a "destpage" parameter gices the name of the page the -content is going to (different for inlined pages). 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 -parameters passed to a [[PreProcessorDirective]], etc, it's better to just -return the error message as the output of the plugin. - -## Html issues - -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 passed -through markdown (or whatever engine is used to htmlize the page) along -with the rest of the page. - -# Other types of hooks - -Beyond PreProcessorDirectives, Other types of hooks that can be used by -plugins include: - -## getopt +### getopt IkiWiki::hook(type => "getopt", id => "foo", call => \&getopt); @@ -77,7 +45,7 @@ settings in %IkiWiki::config. It should take care not to abort if it sees an option it cannot process, and should just skip over those options and leave them in @ARGV. -## checkconfig +### checkconfig IkiWiki::hook(type => "checkconfig", id => "foo", call => \&checkconfig); @@ -86,7 +54,7 @@ configuration. It's called early in the 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 +### filter IkiWiki::hook(type => "filter", id => "foo", call => \&filter); @@ -94,7 +62,32 @@ 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. -## htmlize +### preprocess + +Adding a [[PreProcessorDirective]] 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 brackets 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, while a "destpage" parameter gices the name of the page the +content is going to (different for inlined pages). 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. + +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. + +### htmlize IkiWiki::hook(type => "htmlize", id => "ext", call => \&htmlize); @@ -103,7 +96,10 @@ 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. -## pagetemplate +The function is passed named parameters: "page" and "content" and should +return the htmlized content. + +### pagetemplate IkiWiki::hook(type => "pagetemplate", id => "foo", call => \&pagetemplate); @@ -116,31 +112,37 @@ used to generate the page. The function can manipulate that template object. The most common thing to do is probably to call $template->param() to add -a new custom parameter to the template. Note that in order to be robust, -it's a good idea to check whether the template has a variable before trying -to set it, as setting a variable that's not present is an error. +a new custom parameter to the template. - if ($template->query(name => 'foo')) { - $template->param("foo" => "bar"); - } - -## sanitize +### sanitize IkiWiki::hook(type => "sanitize", id => "foo", call => \&sanitize); 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. +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. + +### format + + IkiWiki::hook(type => "format", id => "foo", call => \&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. -## delete +The function is passed named parameters: "page" and "content", and +should return the formatted content. + +### delete IkiWiki::hook(type => "delete", id => "foo", call => \&delete); 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 +### change IkiWiki::hook(type => "change", id => "foo", call => \&render); @@ -148,7 +150,7 @@ 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 +### cgi IkiWiki::hook(type => "cgi", id => "foo", call => \&cgi); @@ -157,7 +159,7 @@ 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. -## savestate +### savestate IkiWiki::hook(type => "savestate", id => "foo", call => \&savestate); @@ -165,13 +167,20 @@ This hook is called wheneven ikiwiki normally saves its state, just before the state is saved. The function can save other state, modify values before they're saved, etc. -# Wiki configuration +## 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. + +## 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. -# 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: @@ -183,17 +192,17 @@ use the following hashes, using a page name as the key: * `%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::depends` contains a [[GlobList]] that is used to specify other +* `%IkiWiki::depends` contains a [[PageSpec]] that is used to specify other pages that a page depends on. If one of its dependencies is updated, the page will also get rebuilt. 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. + parameters the page name and a [[PageSpec]] of dependencies to add. * `%IkiWiki::forcerebuild` any pages set as the keys to this hash will be treated as if they're modified and rebuilt. -# A note on generating html links +## Generating html links Many plugins need to generate html links and add them to a page. This is done by using the `IkiWiki::htmllink` function. The usual way to call @@ -210,7 +219,7 @@ Here $destpage is the inlining page. A destpage parameter is passed to some of the hook functions above; the ones that are not passed it are not used during inlining and don't need to worry about this issue. -# 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