instead of over and over. Typical speedup is ~4x. Max possible speedup:

[ikiwiki.git] / doc / plugins / write.mdwn

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 8492b1756ccb54733295eaa2248b76b6d0177f1a..5cace0911c1f2d6cf3b6f40e0c4371a838d8b1e2 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -30,6 +30,12 @@ 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.
 
+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.
+
 ## Types of hooks
 
 In roughly the order they are called.
@@ -64,6 +70,14 @@ 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` and should return the filtered content.
 
+### scan
+
+       hook(type => "scan", id => "foo", call => \&scan);
+
+This is identical to a preprocess hook (see below), except that it is
+called in the initial pass that scans pages for data that will be used in
+later passes. Scan hooks are the only hook that should modify 
+
 ### preprocess
 
 Adding a [[PreProcessorDirective]] is probably the most common use of a