X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/18b3e970ffcc0f74d68538b7094f76442a294609..5ddd6d95d6933f55066192ca750a6e26e4ce36e4:/doc/plugins/write.mdwn?ds=inline diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn index 4dc55e302..3976f9adf 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 @@ -19,7 +19,7 @@ that can be fleshed out to make a useful plugin. `IkiWiki::Plugin::pagecount` is another simple example. All perl plugins should `use IkiWiki` to import the ikiwiki plugin interface. It's a good idea to include the version number of the plugin interface that your plugin -expects: `use IkiWiki 2.00`. +expects: `use IkiWiki 3.00`. An external plugin is an executable program. It can be written in any language. Its interface to ikiwiki is via XML RPC, which it reads from @@ -55,8 +55,8 @@ 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 -hook being run first. +after all other hooks of its type, and an optional "first" parameter makes +it run first. Useful if the hook depends on some other hook being run first. ## Types of hooks @@ -98,7 +98,7 @@ function is passed no values. 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 +array of files that will be rebuilt, and can modify the array, either adding or removing files from it. ### scan @@ -107,8 +107,8 @@ adding or removing files from it. 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. +mostly used to scan the page for [[WikiLinks|ikiwiki/WikiLink]], 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. @@ -123,34 +123,42 @@ make arbitrary changes. The function is passed named parameters "page", ### preprocess -Adding a [[ikiwiki/PreProcessorDirective]] is probably the most common use +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. (As an -optimisation, if your preprocessor hook is called in a void contets, you -can assume it's being run in scan mode.) +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` (typically by calling `add_link`). 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 -[[ikiwiki/PreProcessorDirective]] output is sanitised, which may limit what +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 @@ -160,13 +168,14 @@ htmlize the page) along with the rest of the page. hook(type => "linkify", id => "foo", call => \&linkify); -This hook is called to convert [[WikiLinks|WikiLink]] on the page into html +This hook is called to convert [[WikiLinks|ikiwiki/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`. +for the links on the page and adds them to `%links` (typically by calling +`add_link`). ### htmlize @@ -180,6 +189,18 @@ 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 the extension will not be stripped from the source filename when +generating the page. + +If `hook` is passed an optional "noextension" parameter, set to a true +value, then the id parameter specifies not a filename extension, but +a whole filename that can be htmlized. This is useful for files +like `Makefile` that have no extension. + +If `hook` is passed an optional "longname" parameter, this value is used +when prompting a user to choose a page type on the edit page form. + ### pagetemplate hook(type => "pagetemplate", id => "foo", call => \&pagetemplate); @@ -189,7 +210,7 @@ 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. @@ -216,6 +237,17 @@ modify the body of a page after it has been fully converted to html. 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 hook(type => "format", id => "foo", call => \&format); @@ -280,7 +312,7 @@ can check if the session object has a "name" parameter set. ### canedit - hook(type => "canedit", id => "foo", call => \&pagelocked); + hook(type => "canedit", id => "foo", call => \&canedit); This hook can be used to implement arbitrary access methods to control when a page can be edited using the web interface (commits from revision control @@ -298,6 +330,47 @@ 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. +### canremove + + hook(type => "canremove", id => "foo", call => \&canremove); + +This hook can be used to implement arbitrary access methods to control +when a page can be removed using the web interface (commits from +revision control bypass it). It works exactly like the `canedit` hook, +but is passed the named parameters `cgi` (a CGI object), `session` +(a session object) and `page` (the page subject to deletion). + +### canrename + + hook(type => "canrename", id => "foo", call => \&canrename); + +This hook can be used to implement arbitrary access methods to control when +a page can be renamed using the web interface (commits from revision control +bypass it). It works exactly like the `canedit` hook, +but is passed the named parameters `cgi` (a CGI object), `session` (a +session object), `src`, `srcfile`, `dest` and `destfile`. + +### checkcontent + + hook(type => "checkcontent", id => "foo", call => \&checkcontent); + +This hook is called to check the content a user has entered on a page, +before it is saved, and decide if it should be allowed. + +It is passed named parameters: `content`, `page`, `cgi`, and `session`. If +the content the user has entered is a comment, it may also be passed some +additional parameters: `author`, `url`, and `subject`. The `subject` +parameter may also be filled with the user's comment about the change. + +Note: When the user edits an existing wiki page, this hook is also +passed a `diff` named parameter, which will include only the lines +that they added to the page, or modified. + +The hook should return `undef` on success. If the content is disallowed, it +should return a message stating what the problem is, or a function +that can be run to perform whatever action is necessary to allow the user +to post the content. + ### editcontent hook(type => "editcontent", id => "foo", call => \&editcontent); @@ -314,7 +387,7 @@ 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 @@ -337,11 +410,97 @@ 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, once per page linking to the renamed page's old location. +The hook is passed named parameters: `page`, `oldpage`, `newpage`, and +`content`, and should try to modify the content of `page` to reflect +the name change. For example, by converting links to point to the +new page. + +### rename + + hook(type => "rename", id => "foo", call => \&rename); + +When a page or set of pages is renamed, the referenced function is +called for every page, and is passed named parameters: + +* `torename`: a reference to a hash with keys: `src`, `srcfile`, + `dest`, `destfile`, `required`. +* `cgi`: a CGI object +* `session`: a session object. + +Such a hook function returns any additional rename hashes it wants to +add. This hook is applied recursively to returned additional rename +hashes, so that it handles the case where two plugins use the hook: +plugin A would see when plugin B adds a new file to be renamed. + +### 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 [[ikiwiki/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 '2.00'; + use IkiWiki '3.00'; This will import several variables and functions into your plugin's namespace. These variables and functions are the ones most plugins need, @@ -356,14 +515,14 @@ 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}{$key}`. +use `$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 `$id` must be the same @@ -376,6 +535,15 @@ When pages are deleted, ikiwiki automatically deletes their pagestate too. Note that page state does not persist across wiki rebuilds, only across wiki updates. +### %wikistate + +The `%wikistate` hash can be used by a plugin to store persistant state +that is not bound to any one page. To set a value, use +`$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 If your plugin needs to access data about other pages in the wiki. It can @@ -387,7 +555,7 @@ use the following hashes, using a page name as the key: destination file. * `%pagesources` contains the name of the source file for each page. -Also, the %IkiWiki::version variable contains the version number for the +Also, the `%IkiWiki::version` variable contains the version number for the ikiwiki program. ### Library functions @@ -413,7 +581,7 @@ function that is called after the error message is printed, to do any final cleanup. If called inside a preprocess hook, error() does not abort the entire -wiki build, but instead replaces the [[ikiwiki/PreProcessorDirective]] with +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 @@ -422,7 +590,7 @@ 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`. @@ -431,6 +599,9 @@ 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($$)` Makes the specified page depend on the specified [[ikiwiki/PageSpec]]. @@ -445,6 +616,19 @@ The most often used is "location", which specifies the location the PageSpec should match against. If not passed, relative PageSpecs will match relative to the top of the wiki. +#### `pagespec_match_list($$;@)` + +Passed a reference to a list of page names, and [[ikiwiki/PageSpec]], +returns the set of pages that match the [[ikiwiki/PageSpec]]. + +Additional named parameters can be passed, to further limit the match. +The most often used is "location", which specifies the location the +PageSpec should match against. If not passed, relative PageSpecs will match +relative to the top of the wiki. + +Unlike pagespec_match, this may throw an error if there is an error in +the pagespec. + #### `bestlink($$)` Given a page and the text of a link on the page, determine which @@ -457,7 +641,7 @@ pages, as described in [[ikiwiki/SubPage/LinkingRules]]. Many plugins need to generate html links and add them to a page. This is done by using the `htmllink` function. The usual way to call -`htmlllink` is: +`htmllink` is: htmllink($page, $page, $link) @@ -507,6 +691,16 @@ A failure to write the file will result in it dying with an error. If the destination directory doesn't exist, it will first be created. +The filename and directory are separate parameters because of +some security checks done to avoid symlink attacks. Before writing a file, +it checks to make sure there's not a symlink with its name, to avoid +following the symlink. If the filename parameter includes a subdirectory +to put the file in, it also checks if that subdirectory is a symlink, etc. +The directory parameter, however, is not checked for symlinks. So, +generally the directory parameter is a trusted toplevel directory like +the srcdir or destdir, and any subdirectories of this are included in the +filename parameter. + #### `will_render($$)` Given a page name and a destination file name (not including the base @@ -533,6 +727,23 @@ 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. +#### `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($)` + +This converts text that could have been entered by the user as a +[[ikiwiki/WikiLink]] into a wiki page name. + #### `srcfile($;$)` Given the name of a source file in the wiki, searches for the file in @@ -562,17 +773,35 @@ time. 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`. -#### `targetpage($$)` +If the third parameter is passed and is true, an absolute url will be +constructed instead of the default relative url. + +#### `newpagefile($$)` + +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($$;$)` Passed a page and an extension, returns the filename that page will be rendered to. +Optionally, a third parameter can be passed, to specify the preferred +filename of the page. For example, `targetpage("foo", "rss", "feed")` +will yield something like `foo/feed.rss`. + +#### `add_link($$)` + +This adds a link to `%links`, ensuring that duplicate links are not +added. Pass it the page that contains the link, and the link text. + ## Miscellaneous ### Internal use pages @@ -583,22 +812,138 @@ 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 +generally shouldn't contain [[WikiLinks|ikiwiki/WikiLink]] 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]] also uses pluggable -perl modules. These are in the `IkiWiki::RCS` namespace, for example -`IkiWiki::RCS::svn`. +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()` + +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. + +#### `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 @@ -607,21 +952,104 @@ It's also possible to write plugins that add new functions to IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is 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. +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. If the match cannot be +attempted at all, for any page, it can instead return an +IkiWiki::ErrorReason object explaining why. ### 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. +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. +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|ikiwiki/WikiLink]]. + +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 `