Merge commit 'baaa848f6c06b0b3a59677d3551e130c65e5fde7' into sipb

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

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 1010e76e400bab3e479c081873437d37db0095f1..707622956988b4f1b93fff55ec6d82b903a2972c 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -588,36 +588,6 @@ describes the plugin as a whole. For example:
 This hook is used to inject C code (which it returns) into the `main`
 function of the ikiwiki wrapper when it is being generated.
 
-### sort
-
-       hook(type => "sort", id => "foo", call => \&sort_by_foo);
-
-This hook adds an additional [[ikiwiki/pagespec/sorting]] order or overrides
-an existing one.
-
-The callback is given two page names followed by the parameter as arguments, and
-returns negative, zero or positive if the first page should come before,
-close to (i.e. undefined order), or after the second page.
-
-For instance, the built-in `title` sort order could be reimplemented as
-
-       sub sort_by_title {
-               pagetitle(basename($_[0])) cmp pagetitle(basename($_[1]));
-       }
-
-and to sort by an arbitrary `meta` value, you could use:
-
-       # usage: sort="meta(description)"
-       sub sort_by_meta {
-               my $param = $_[2];
-               error "sort=meta requires a parameter" unless defined $param;
-               my $left = $pagestate{$_[0]}{meta}{$param};
-               $left = "" unless defined $left;
-               my $right = $pagestate{$_[1]}{meta}{$param};
-               $right = "" unless defined $right;
-               return $left cmp $right;
-       }
-
 ## Exported variables
 
 Several variables are exported to your plugin when you `use IkiWiki;`
@@ -663,6 +633,22 @@ reference. Do not modify this hash directly; call `add_link()`.
 
        $links{"foo"} = ["bar", "baz"];
 
+### `%typedlinks`
+
+The `%typedlinks` hash records links of specific types. Do not modify this
+hash directly; call `add_link()`. The keys are page names, and the values
+are hash references. In each page's hash reference, the keys are link types
+defined by plugins, and the values are hash references with link targets
+as keys, and 1 as a dummy value, something like this:
+
+       $typedlinks{"foo"} = {
+               tag => { short_word => 1, metasyntactic_variable => 1 },
+               next_page => { bar => 1 },
+       };
+
+Ordinary [[WikiLinks|ikiwiki/WikiLink]] appear in `%links`, but not in
+`%typedlinks`.
+
 ### `%pagesources`
 
 The `%pagesources` has can be used to look up the source filename
@@ -748,7 +734,10 @@ Additional named parameters can be specified:
 * `filter` is a reference to a function, that is called and passed a page,
   and returns true if the page should be filtered out of the list.
 * `sort` specifies a sort order for the list. See
-  [[ikiwiki/PageSpec/sorting]] for the avilable sort methods.
+  [[ikiwiki/PageSpec/sorting]] for the avilable sort methods. Note that
+  if a sort method is specified that depends on the
+  page content (such as 'meta(foo)'), the deptype needs to be set to
+  a content dependency.
 * `reverse` if true, sorts in reverse.
 * `num` if nonzero, specifies the maximum number of matching pages that
   will be returned.
@@ -969,11 +958,14 @@ 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($$)`
+### `add_link($$;$)`
 
 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.
 
+An optional third parameter sets the link type. If not specified,
+it is an ordinary [[ikiwiki/WikiLink]].
+
 ## Miscellaneous
 
 ### Internal use pages
@@ -1140,6 +1132,24 @@ For example, "backlink(foo)" is influenced by the contents of page foo;
 they match; "created_before(foo)" is influenced by the metadata of foo;
 while "glob(*)" is not influenced by the contents of any page.
 
+### Sorting plugins
+
+Similarly, it's possible to write plugins that add new functions as
+[[ikiwiki/pagespec/sorting]] methods. To achieve this, add a function to
+the IkiWiki::SortSpec package named `cmp_foo`, which will be used when sorting
+by `foo` or `foo(...)` is requested.
+
+The names of pages to be compared are in the global variables `$a` and `$b`
+in the IkiWiki::SortSpec package. The function should return the same thing
+as Perl's `cmp` and `<=>` operators: negative if `$a` is less than `$b`,
+positive if `$a` is greater, or zero if they are considered equal. It may
+also raise an error using `error`, for instance if it needs a parameter but
+one isn't provided.
+
+The function will also be passed one or more parameters. The first is
+`undef` if invoked as `foo`, or the parameter `"bar"` if invoked as `foo(bar)`;
+it may also be passed additional, named parameters.
+
 ### Setup plugins
 
 The ikiwiki setup file is loaded using a pluggable mechanism. If you look