X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/6c89a635bb0715fd06b0061692fe39b3e79fcad7..9fe92640eb46f0afa24993b5c4957c054e62ae4d:/doc/plugins/write.mdwn?ds=sidebyside diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn index 0c192eb64..abcabbdc3 100644 --- a/doc/plugins/write.mdwn +++ b/doc/plugins/write.mdwn @@ -3,7 +3,7 @@ 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]] +[[!toc levels=2]] ## Types of plugins @@ -46,11 +46,13 @@ being edited. 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 @@ -82,15 +84,35 @@ configuration. It's called early in the startup process. The 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. +### 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); @@ -101,42 +123,64 @@ make arbitrary changes. The function is passed named parameters "page", ### preprocess -Adding a [[PreProcessorDirective]] is probably the most common use of a -plugin. +Adding a preprocessor [[ikiwiki/directive]] is probably the most common use +of a plugin. 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 gives the name of the page the -content is going to (different for inlined pages), and a "preview" -parameter is set to a true value if the page is being previewed. 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 +Replace "foo" with the command name that will be used for the preprocessor directive. -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 -be run twice per page build, so avoid doing it for expensive hooks. +Each time the directive is processed, the referenced function (`preprocess` +in the example above) is called. Whatever the function returns goes onto +the page in place of the directive. Or, if the function aborts using +`error()`, the directive will be replaced with the error message. + +The function is passed named parameters. First come the parameters set +in the preprocessor directive. These are passed in the same order as +they're in the directive, and if the preprocessor directive contains a bare +parameter (example: `\[[!foo param]]`), that parameter will be passed with +an empty value. + +After the parameters from the preprocessor directive some additional ones +are passed: A "page" parameter gives the name of the page that embedded the +preprocessor directive, while a "destpage" parameter gives the name of the +page the content is going to (different for inlined pages), and a "preview" +parameter is set to a true value if the page is being previewed. + +If `hook` is passed an optional "scan" parameter, set to a true value, this +makes the hook be called during the preliminary scan that ikiwiki makes of +updated pages, before begining to render pages. This should be done 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. (As an +optimisation, if your preprocessor hook is called in a void context, you +can assume it's being run in scan mode, and avoid doing expensive things at +that point.) 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. +preprocessor [[ikiwiki/directive]] 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. + +### 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`. ### 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. @@ -144,6 +188,10 @@ languages to ikiwiki. The function is passed named parameters: "page" and "content" and should return the htmlized content. +If `hook` is passed an optional "keepextension" parameter, set to a true +value, then this extension will not be stripped from the source filename when +generating the page. + ### pagetemplate hook(type => "pagetemplate", id => "foo", call => \&pagetemplate); @@ -153,7 +201,7 @@ 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 "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. @@ -164,7 +212,7 @@ a new custom parameter to the template. 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 @@ -177,8 +225,19 @@ want to change the default ("page.tmpl"). Template files are looked for in 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 @@ -186,7 +245,9 @@ should return the sanitized content. 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. @@ -212,16 +273,19 @@ source files that were rendered. 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 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 @@ -246,10 +310,16 @@ 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. -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 -`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 @@ -267,7 +337,7 @@ It can modify the content as desired, and should return the content. 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 @@ -279,24 +349,89 @@ 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. -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. +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 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. +### renamepage + + hook(type => "renamepage", id => "foo", call => \&renamepage); + +This hook is called by the [[plugins/rename]] plugin when it renames +something. The hook is passed named parameters: `page`, `oldpage`, +`newpage`, and `content`, and should try to modify the content to reflect +the name change. For example, by converting links to point to the new page. + +### getsetup + + hook(type => "getsetup", id => "foo", call => \&getsetup); + +This hooks is not called during normal operation, but only when setting up +the wiki, or generating a setup file. Plugins can use this hook to add +configuration options. + +The hook is passed no parameters. It returns data about the configuration +options added by the plugin. It can also check if the plugin is usable, and +die if not, which will cause the plugin to not be offered in the configuration +interface. + +The data returned is a list of `%config` options, followed by a hash +describing the option. There can also be an item named "plugin", which +describes the plugin as a whole. For example: + + return + option_foo => { + type => "boolean", + description => "enable foo?", + advanced => 1, + safe => 1, + rebuild => 1, + }, + option_bar => { + type => "string", + example => "hello", + description => "option bar", + safe => 1, + rebuild => 0, + }, + plugin => { + description => "description of this plugin", + safe => 1, + rebuild => 1, + }, + +* `type` can be "boolean", "string", "integer", "pagespec", + or "internal" (used for values that are not user-visible). The type is + the type of the leaf values; the `%config` option may be an array or + hash of these. +* `example` can be set to an example value. +* `description` is a short description of the option. +* `link` is a link to further information about the option. This can either + be a wikilink, or an url. +* `advanced` can be set to true if the option is more suitable for advanced + users. +* `safe` should be false if the option should not be displayed in unsafe + configuration methods, such as the web interface. Anything that specifies + a command to run, a path on disk, or a regexp should be marked as unsafe. + If a plugin is marked as unsafe, that prevents it from being + enabled/disabled. +* `rebuild` should be true if changing the option (or enabling/disabling + the plugin) will require a wiki rebuild, false if no rebuild is needed, + and undef if a rebuild could be needed in some circumstances, but is not + strictly required. + ## Plugin interface 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, @@ -311,7 +446,34 @@ it's not exported, the wise choice is to not use it. 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. +your ikiwiki setup file, 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}{$key}`. + +The `$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. + +Note that page state does not persist across wiki rebuilds, only across +wiki updates. + +### %wikistate + +The `%wikistate` hash can be used by a plugin to store persistant state +that is not bound to any one page. To set a value, use +`$wikistate{$id}{$key}=$value, where `$value` is anything Storable can +serialize, `$key` is any string you like, and `$id` must be the same as the +"id" parameter passed to `hook()` when registering the plugin, so that the +state can be dropped if the plugin is no longer used. ### Other variables @@ -349,15 +511,17 @@ Aborts with an error message. If the second parameter is passed, it is a function that is called after the error message is printed, to do any final cleanup. -Note that while any plugin can use this for a fatal error, plugins should -try to avoid dying on bad input, as that will halt the entire wiki build -and make the wiki unusable. So for example, if a [[PreProcessorDirective]] -is passed bad parameters, it's better to return an error message, which can -appear on the wiki page, rather than calling error(). +If called inside a preprocess hook, error() does not abort the entire +wiki build, but instead replaces the preprocessor [[ikiwiki/directive]] with +a version containing the error message. + +In other hooks, error() is a fatal error, so use with care. Try to avoid +dying on bad input when building a page, as that will halt +the entire wiki build and make the wiki unusable. #### `template($;@)` -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`. @@ -366,14 +530,17 @@ parameters are passed to `HTML::Template->new`. Passed a page name, returns the base name that will be used for a the html page created from it. (Ie, it appends ".html".) +Use this when constructing the filename of a html file. Use `urlto` when +generating a link to a page. + #### `add_depends($$)` -Makes the specified page depend on the specified [[PageSpec]]. +Makes the specified page depend on the specified [[ikiwiki/PageSpec]]. #### `pagespec_match($$;@)` -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 @@ -386,7 +553,7 @@ 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 -pages, as described in [[SubPage/LinkingRules]]. +pages, as described in [[ikiwiki/SubPage/LinkingRules]]. #### `htmllink($$$;@)` @@ -412,7 +579,8 @@ 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 -* 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($;$)` @@ -445,8 +613,17 @@ If the destination directory doesn't exist, it will first be created. 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 changed to no longer render +them. will_render also does a few important security checks. #### `pagetype($)` @@ -458,50 +635,317 @@ a type that ikiwiki knowns how to htmlize. Otherwise, returns undef. Given the name of a source file, returns the name of the wiki page that corresponds to that file. -#### `srcfile($)` +#### `pagetitle($)` + +Give the name of a wiki page, returns a version suitable to be displayed as +the page's title. This is accomplished by de-escaping escaped characters in +the page name. "_" is replaced with a space, and '__NN__' is replaced by +the UTF character with code NN. + +#### `titlepage($)` + +This performs the inverse of `pagetitle`, ie, it converts a page title into +a wiki page name. + +#### `linkpage($)` + +This converts text that could have been entered by the user as a +[[WikiLink]] into a wiki page name. + +#### `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. + +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. -#### `displaytime($)` +#### `add_underlay($)` + +Adds a directory to the set of underlay directories that ikiwiki will +search for files. + +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. +The optional second parameter is a strftime format to use to format the +time. + #### `gettext` This is the standard gettext function, although slightly optimised. -#### `urlto($$)` +#### `urlto($$;$)` Construct a relative url to the first parameter from the page named by the second. The first parameter can be either a page name, or some other destination file, as registered by `will_render`. +If the third parameter is passed and is true, an absolute url will be +constructed instead of the default relative url. + +#### `newpagefile($$)` + +This can be called when creating a new page, to determine what filename +to save the page to. It's passed a page name, and its type, and returns +the name of the file to create, relative to the srcdir. + #### `targetpage($$)` Passed a page and an extension, returns the filename that page will be rendered to. -## RCS plugins +## Miscellaneous + +### Internal use pages + +Sometimes it's useful to put pages in the wiki without the overhead of +having them be rendered to individual html files. Such internal use pages +are collected together to form the RecentChanges page, for example. + +To make an internal use page, register a filename extension that starts +with "_". Internal use pages cannot be edited with the web interface, +generally shouldn't contain wikilinks or preprocessor directives (use +either on them with extreme caution), and are not matched by regular +PageSpecs glob patterns, but instead only by a special `internal()` +[[ikiwiki/PageSpec]]. + +### RCS plugins + +ikiwiki's support for [[revision_control_systems|rcs]] is also done via +plugins. See [[RCS_details|rcs/details]] for some more info. + +RCS plugins must register a number of hooks. Each hook has type 'rcs', +and the 'id' field is set to the name of the hook. For example: + + hook(type => "rcs", id => "rcs_update", call => \&rcs_update); + hook(type => "rcs", id => "rcs_prepedit", call => \&rcs_prepedit); + +#### `rcs_update()` -ikiwiki's support for [[revision_control_systems|rcs]] also uses pluggable -perl modules. These are in the `IkiWiki::RCS` namespace, for example -`IkiWiki::RCS::svn`. +Updates the working directory with any remote changes. -Each RCS plugin must support all the `IkiWiki::rcs_*` functions. -See IkiWiki::RCS::Stub for the full list of functions. It's ok if -`rcs_getctime` does nothing except for throwing an error. +#### `rcs_prepedit($)` -See [[RCS_details|rcs/details]] for some more info. +Is passed a file to prepare to edit. It can generate and return an arbitrary +token, that will be passed into `rcs_commit` when committing. For example, +it might return the current revision ID of the file, and use that +information later when merging changes. -## PageSpec plugins +#### `rcs_commit($$$;$$)` + +Passed a file, message, token (from `rcs_prepedit`), user, and ip address. +Should try to commit the file. Returns `undef` on *success* and a version +of the page with the rcs's conflict markers on failure. + +#### `rcs_commit_staged($$$)` + +Passed a message, user, and ip address. Should commit all staged changes. +Returns undef on success, and an error message on failure. + +Changes can be staged by calls to `rcs_add, `rcs_remove`, and +`rcs_rename`. + +#### `rcs_add($)` + +Adds the passed file to the archive. The filename is relative to the root +of the srcdir. + +Note that this should not commit the new file, it should only +prepare for it to be committed when rcs_commit (or `rcs_commit_staged`) is +called. Note that the file may be in a new subdir that is not yet in +to version control; the subdir can be added if so. + +#### `rcs_remove($)` + +Remove a file. The filename is relative to the root of the srcdir. + +Note that this should not commit the removal, it should only prepare for it +to be committed when `rcs_commit` (or `rcs_commit_staged`) is called. Note +that the new file may be in a new subdir that is not yet in version +control; the subdir can be added if so. + +#### `rcs_rename($$)` + +Rename a file. The filenames are relative to the root of the srcdir. + +Note that this should not commit the rename, it should only +prepare it for when `rcs_commit` (or `rcs_commit_staged`) is called. +The new filename may be in a new subdir, that is not yet added to +version control. If so, the subdir will exist already, and should +be added to revision control. + +#### `rcs_recentchanges($)` + +Examine the RCS history and generate a list of recent changes. +The parameter is how many changes to return. + +The data structure returned for each change is: + + { + rev => # the RCSs id for this commit + user => # name of user who made the change, + committype => # either "web" or the name of the rcs, + when => # time when the change was made, + message => [ + { line => "commit message line 1" }, + { line => "commit message line 2" }, + # etc, + ], + pages => [ + { + page => # name of page changed, + diffurl => # optional url to a diff of changes + }, + # repeat for each page changed in this commit, + ], + } + +#### `rcs_diff($)` + +The parameter is the rev from `rcs_recentchanges`. +Should return a list of lines of the diff (including \n) in list +context, and the whole diff in scalar context. + +#### `rcs_getctime($)` + +This is used to get the page creation time for a file from the RCS, by looking +it up in the history. + +It's ok if this is not implemented, and throws an error. + +#### `rcs_receive()` + +This is called when ikiwiki is running as a pre-receive hook (or +equivalent), and is testing if changes pushed into the RCS from an +untrusted user should be accepted. This is optional, and doesn't make +sense to implement for all RCSs. + +It should examine the incoming changes, and do any sanity +checks that are appropriate for the RCS to limit changes to safe file adds, +removes, and changes. If something bad is found, it should exit +nonzero, to abort the push. Otherwise, it should return a list of +files that were changed, in the form: + + { + file => # name of file that was changed + action => # either "add", "change", or "remove" + path => # temp file containing the new file content, only + # needed for "add"/"change", and only if the file + # is an attachment, not a page + } + +The list will then be checked to make sure that each change is one that +is allowed to be made via the web interface. + +### 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 -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 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 a setup file, 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. They should also implement a +`gendump` function. + +By the way, to parse a ikiwiki setup file and populate `%config`, a +program just needs to do something like: +`use IkiWiki::Setup; IkiWiki::Setup::load($filename)` + +### Function overriding + +Sometimes using ikiwiki's pre-defined hooks is not enough. Your plugin +may need to replace one of ikiwiki's own functions with a modified version, +or wrap one of the functions. + +For example, your plugin might want to override `displaytime`, to change +the html markup used when displaying a date. Or it might want to override +`IkiWiki::formattime`, to change how a date is formatted. Or perhaps you +want to override `bestlink` and change how ikiwiki deals with WikiLinks. + +By venturing into this territory, your plugin is becoming tightly tied to +ikiwiki's internals. And it might break if those internals change. But +don't let that stop you, if you're brave. + +Ikiwiki provides an `inject()` function, that is a powerful way to replace +any function with one of your own. This even allows you to inject a +replacement for an exported function, like `bestlink`. Everything that +imports that function will get your version instead. Pass it the name of +the function to replace, and a new function to call. + +For example, here's how to replace `displaytime` with a version using HTML 5 +markup: + + inject(name => 'IkiWiki::displaytime', call => sub { + return ""; + }); + +Here's how to wrap `bestlink` with a version that tries to handle +plural words: + + my $origbestlink=\&bestlink; + inject(name => 'IkiWiki::bestlink', call => \&mybestlink); + + sub deplural ($) { + my $word=shift; + $word =~ s/e?s$//; # just an example :-) + return $word; + } + + sub mybestlink ($$) { + my $page=shift; + my $link=shift; + my $ret=$origbestlink->($page, $link); + if (! length $ret) { + $ret=$origbestlink->($page, deplural($link)); + } + return $ret; + } + +### Javascript + +Some plugins use javascript to make ikiwiki look a bit more web-2.0-ish. + +All javascript code should be put in `.js` files in the `javascript` +underlay, and plugins using those files can enable use of the underlay by +calling `add_underlay("javascript");` in their `import` function. + +You'll have to arrange for `