[[!tag plugins/meta patch]]
[[!template id=gitbranch branch=jon/defaultmeta author="[[Jon]]"]]

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 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..3132257 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 ($$;@) {
    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]]

> This doesn't support multiple-argument meta directives like
> `link=x rel=y`, or meta directives with special side-effects like
> `updated`.
>
> The first could be solved (if you care) by a syntax like this:
>
>     meta_defaults => [
>         { copyright => "© me" },
>         { link => "about:blank", rel => "silly", },
>     ]
>
> The second could perhaps be solved by invoking `meta::preprocess` from within
> `scan` (which might be a simplification anyway), although this is complicated
> by the fact that some (but not all!) meta headers are idempotent.
> 
> --[[smcv]]

>> Thanks for your comment. Tonight I had a go at implementing the syntax
>> you propose here. I decided the simplest thing to do might be for the scan
>> subroutine to convert any hashes found in the meta_defaults list into calls
>> to the preprocess routine. I've got a bit stuck trying to convert a hash to
>> a named parameter list (or just a subroutine parameter list that is). I may
>> try to look again in the morning (brain a bit sleepy)
>>
>> ...and on writing this comment I see your second suggestion was essentially
>> to do exactly that :) -- [[Jon]]