add allow_site-wide_meta_definitions.mdwn

doc/todo/allow_site-wide_meta_definitions.mdwn

@@ -0,0 +1,60 @@
+I'd like to define [[plugins/meta]] values to apply across all pages
+site-wide unless the pages define their own: default values for meta
+definitions essentially.
+
+Here's a patch[[!tag patch]] to achieve this (also in the "defaultmeta" branch of
+my github ikiwiki fork):
+
+    diff --git a/IkiWiki/Plugin/meta.pm b/IkiWiki/Plugin/meta.pm
+    index b229592..a307db4 100644
+    --- a/IkiWiki/Plugin/meta.pm
+    +++ b/IkiWiki/Plugin/meta.pm
+    @@ -13,6 +13,7 @@ sub import {
+            hook(type => "needsbuild", id => "meta", call => \&needsbuild);
+            hook(type => "preprocess", id => "meta", call => \&preprocess, scan => 1);
+            hook(type => "pagetemplate", id => "meta", call => \&pagetemplate);
+    +       hook(type => "scan", id => "meta", call => \&scan);
+     }
+     
+     sub getsetup () {
+    @@ -302,6 +303,15 @@ sub match {
+            }
+     }
+     
+    +sub scan() {
+    +       my %params = @_;
+    +       my $page = $params{page};
+    +    foreach my $type (map { s/^meta_//; $_ } grep /^meta_/, keys %config) {
+    +               $pagestate{$page}{meta}{$type} = $config{"meta_$type"}
+    +                       unless defined $pagestate{$page}{meta}{$type};
+    +       }
+    +}
+    +
+     package IkiWiki::PageSpec;
+     
+     sub match_title ($$;@) {
+    @@ -324,4 +334,5 @@ sub match_copyright ($$;@) {
+            IkiWiki::Plugin::meta::match("copyright", @_);
+     }
+     
+    +
+     1
+    diff --git a/doc/ikiwiki/directive/meta.mdwn b/doc/ikiwiki/directive/meta.mdwn
+    index 000f461..200c4b2 100644
+    --- a/doc/ikiwiki/directive/meta.mdwn
+    +++ b/doc/ikiwiki/directive/meta.mdwn
+    @@ -12,6 +12,12 @@ also specifies some additional sub-parameters.
+     The field values are treated as HTML entity-escaped text, so you can include
+     a quote in the text by writing `"` and so on.
+     
+    +You can also define site-wide defaults for meta values by including them
+    +in your setup file, e.g.
+    +
+    +       meta_copyright => "Copyright 2007 by Joey Hess",
+    +       meta_license   => "GPL v2+",
+    +
+     Supported fields:
+     
+     * title
+
+-- [[Jon]]