X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/b2dea99417ebfee3d448ab6b49ca58cb2780258d..8d9ec24232ede981face0c3eafbce71b74c4725a:/doc/plugins/write.mdwn

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 183675c53..4dc55e302 100644
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -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
@@ -92,8 +94,6 @@ function is passed no values.
 
 ### needsbuild
 
-
-
 	hook(type => "needsbuild", id => "foo", call => \&needsbuild);
 
 This allows a plugin to manipulate the list of files that need to be
@@ -101,6 +101,18 @@ 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);
@@ -156,23 +168,11 @@ 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`.
 
-### 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.
-
 ### 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.
@@ -213,8 +213,8 @@ 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.
 
 ### format
 
@@ -222,7 +222,9 @@ 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.
@@ -258,9 +260,9 @@ state is loaded, and with no session information.
 
 	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
@@ -331,7 +333,7 @@ called. It can be used to validate the form, but should not display it.
 
 	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.
 
@@ -339,7 +341,7 @@ they're saved, etc.
 
 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,
@@ -363,10 +365,11 @@ 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}`.
 
-`$key` can be any string you like, but `$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.
+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.
 
@@ -409,12 +412,13 @@ 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
-[[ikiwiki/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 [[ikiwiki/PreProcessorDirective]] 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($;@)`
 
@@ -569,7 +573,9 @@ destination file, as registered by `will_render`.
 Passed a page and an extension, returns the filename that page will be
 rendered to.
 
-## Internal use pages
+## 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
@@ -582,7 +588,7 @@ 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
+### RCS plugins
 
 ikiwiki's support for [[revision_control_systems|rcs]] also uses pluggable
 perl modules. These are in the `IkiWiki::RCS` namespace, for example
@@ -594,7 +600,7 @@ See IkiWiki::RCS::Stub for the full list of functions. It's ok if
 
 See [[RCS_details|rcs/details]] for some more info.
 
-## PageSpec plugins
+### PageSpec plugins
 
 It's also possible to write plugins that add new functions to
 [[PageSpecs|ikiwiki/PageSpec]]. Such a plugin should add a function to the
@@ -604,3 +610,18 @@ 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 [[ikiwiki.setup]], 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 `$IkiWiki::Setup::raw_setup` with a reference
+to a hash containing all the config items.
+
+By the way, to parse a ikiwiki setup file, a program just needs to
+do something like `use IkiWiki::Setup; my %setup=IkiWiki::Setup::load($filename)`