X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/157df8591f03ade7504ad732446f125ae8609b05..a79f5ce802693f029de0cd705c36e4e7482160fb:/doc/plugins/write.mdwn diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn index ae2f8b904..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 @@ -26,46 +28,29 @@ 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. +### getopt -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 -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 [[HTMLSanitization]] 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 along with the rest of the page. + IkiWiki::hook(type => "getopt", id => "foo", call => \&getopt); -## Other types of hooks - -Beyond PreProcessorDirectives, Other types of hooks that can be used by -plugins include: +This allows for plugins to perform their own processing of command-line +options and so add options to the ikiwiki command line. It's called during +command line processing, with @ARGV full of any options that ikiwiki was +not able to process on its own. The function should process any options it +can, removing them from @ARGV, and probably recording the configuration +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 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 +This is useful if the plugin needs to check for or modify ikiwiki's +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. @@ -75,11 +60,84 @@ IkiWiki::error if something isn't configured right. 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` should return the filtered content. +`content` and should return the filtered content. + +### 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); + +Runs on the raw 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. + +The function is passed named parameters: "page" and "content" and should +return the htmlized content. + +### pagetemplate + + IkiWiki::hook(type => "pagetemplate", id => "foo", call => \&pagetemplate); + +Each time a page (or part of a blog page, or an rss feed) is rendered, a +[[template|templates]] is filled out. This hook allows modifying that +template. The function is passed named parameters. The "page" and +"destpage" parameters are the same as for a preprocess hook. The "template" +parameter is a `HTML::Template` object that is the template that will be +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. + +### sanitize + + IkiWiki::hook(type => "sanitize", id => "foo", call => \&sanitize); + +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. + +### 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. + +The function is passed named parameters: "page" and "content", and +should return the formatted content. ### delete - IkiWiki::hook(type => "delete", id => "foo", call => \&dele); + 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. @@ -101,6 +159,21 @@ 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 + + IkiWiki::hook(type => "savestate", id => "foo", call => \&savestate); + +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. + +## 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` @@ -119,25 +192,32 @@ 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. + +## 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 +htmlllink is: -## Page templates + htmllink($page, $page, $link) -Plugins are mostly limited to changing the content of pages, to change the -look and feel of the wiki it's generally better to use a stylesheet and -[[templates]]. However, there are some hooks in the templates that plugins -can use to add stuff to the wiki's UI: +Why is $page repeated? Because if a page is inlined inside another, and a +link is placed on it, the right way to make that link is actually: -### Adding content to the page header + htmllink($page, $destpage, $link) -Html that is added to $IkiWiki::config{headercontent} will show up in the -header of the page. One good thing to put here is a search form. +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