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Diffstat (limited to 'doc/plugins')
| -rw-r--r-- | doc/plugins/write.mdwn | 97 |
1 files changed, 78 insertions, 19 deletions
diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn index f2b96b6d9..d94216e17 100644 --- a/doc/plugins/write.mdwn +++ b/doc/plugins/write.mdwn @@ -9,16 +9,73 @@ Ikiwiki is a compiler 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 are loaded. A plugin that inserts the current time into a page, for -example, will insert the build time. Also, as a compiler, ikiwiki avoids -rebuilding pages unless they have changed, so a plugin that prints some -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. The [[tutorial]] has some other examples of ways that ikiwiki -being a compiler may trip up the unwary. +example, will insert the build time. + +Also, as a compiler, ikiwiki avoids rebuilding pages unless they have +changed, so a plugin that prints some 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. + +The [[tutorial]] has some other examples of ways that ikiwiki being a +compiler may trip up the unwary. """]] [[!toc levels=2]] +## Highlevel view of ikiwiki + +Ikiwiki mostly has two modes of operation. It can either be running +as a compiler, building or updating a wiki; or as a cgi program, providing +user interface for editing pages, etc. Almost everything ikiwiki does +is accomplished by calling various hooks provided by plugins. + +### compiler + +As a compiler, starts by calling the `refresh` hook. Then it checks +the wiki's source to find new or changed pages. The `needsbuild` hook is +then called to allow manipulation of the list of pages that need to be +built. + +Now that it knows what pages it needs to build, ikiwiki runs two +compile passes. First, it runs `scan` hooks, which collect metadata about +the pages. Then it runs a page rendering pipeline, by calling in turn these +hooks: `filter`, `preprocess`, `linkify`, `htmlize`, `postscan`, +`pagetemplate`, `sanitize`, `format`. + +After all necessary pages are built, it calls the `change` hook. Finally, +if a page is was deleted, the `delete` hook is called, and the files that +page had previously produced are removed. + +### cgi + +The flow between hooks when ikiwiki is run as a cgi is best illistrated by +an example. + +* *Alice browses to a page and clicks Edit.* +* Ikiwiki is run as a cgi. It assigns Alice a session cookie, and, + by calling the `auth` hooks, sees that she is not yet logged in. +* The `sessioncgi` hooks are then called, and one of them, + from the [[editpage]] plugin, notices that the cgi has been told "do=edit". +* The [[editpage]] plugin calls the `canedit` hook to check if this + page edit is allowed. The [[signinedit]] plugin has a hook that says not: + Alice is not signed in. +* The [[signinedit]] plugin then launches the signin process. A signin + page is built by calling the `formbuilder_setup` hook. +* *Alice signs in with her openid.* +* The [[openid]] plugin's `formbuilder` hook sees that an openid was + entered in the signin form, and redirects to Alice's openid provider. +* Alice's openid provider calls back to ikiwiki. The [[openid]] plugin + has an `auth` hook that finishes the openid signin process. +* Signin complete, ikiwiki returns to what Alice was doing before; editing + a page. +* Now all the `canedit` hooks are happy. The [[editpage]] plugin calls + `formbuilder_setup` to display the page editing form. +* *Alice saves her change to the page.* +* The [[editpage]] plugin's `formbuilder` hook sees that the Save button + was pressed, and calls the `checkcontent` and `editcontent` hooks. + Then it saves the page to disk, and branches into the compiler part + of ikiwiki to refresh the wiki. + ## Types of plugins Most ikiwiki [[plugins]] are written in perl, like ikiwiki. This gives the @@ -530,13 +587,13 @@ function of the ikiwiki wrapper when it is being generated. Several variables are exported to your plugin when you `use IkiWiki;` -### %config +### `%config` 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 your ikiwiki setup file, which sets the hash content to configure the wiki. -### %pagestate +### `%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, @@ -554,7 +611,7 @@ 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 +### `%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 @@ -563,7 +620,7 @@ 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. -### %links +### `%links` The `%links` hash can be used to look up the names of each page that a page links to. The name of the page is the key; the value is an array @@ -571,7 +628,15 @@ reference. Do not modify this hash directly; call `add_link()`. $links{"foo"} = ["bar", "baz"]; -### %destsources +### `%pagesources` + +The `%pagesources` has can be used to look up the source filename +of a page. So the key is the page name, and the value is the source +filename. Do not modify this hash. + + $pagesources{"foo"} = "foo.mdwn"; + +### `%destsources` The `%destsources` hash records the name of the source file used to create each destination file. The key is the output filename (ie, @@ -581,16 +646,10 @@ destination files. Do not modify this hash directly; call `will_render()`. $destsources{"foo/index.html"} = "foo.mdwn"; -### %pagesources - -The `%pagesources` has can be used to look up the source filename -of a page. So the key is the page name, and the value is the source -filename. Do not modify this hash. - - $pagesources{"foo"} = "foo.mdwn"; - ## Library functions +Several functions are exported to your plugin when you `use IkiWiki;` + ### `hook(@)` Hook into ikiwiki's processing. See the discussion of hooks above. |