ikiwiki/doc/todo/allow_site-wide_meta_definitions.mdwn

[[!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.

    <snip old patch, see below for latest>

-- [[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. I've revised the patch to use the config syntax
>> you suggest. I need to perform some more testing to make sure I've
>> addressed the issues you highlight.
>> 
>> I had to patch part of IkiWiki core, the merge routine in Setup, because
>> the use of `possibly_foolish_untaint` was causing the hashrefs at the deep
>> end of the data structure to be converted into strings. The specific change
>> I've made may not be acceptable, though -- I'd appreciate someone providing
>> some feedback on that hunk!

    diff --git a/IkiWiki/Plugin/meta.pm b/IkiWiki/Plugin/meta.pm
    index 6fe9cda..2f8c098 100644
    --- a/IkiWiki/Plugin/meta.pm
    +++ b/IkiWiki/Plugin/meta.pm
    @@ -13,6 +13,8 @@ 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)
    +		if $config{"meta_defaults"};
     }
     
     sub getsetup () {
    @@ -305,6 +307,15 @@ sub match {
     	}
     }
     
    +sub scan() {
    +	my %params = @_;
    +	my $page = $params{page};
    +	foreach my $default (@{$config{"meta_defaults"}}) {
    +		preprocess(%$default, page => $page,
    +			destpage => $page, preview => 0);
    +	}
    +}
    +
     package IkiWiki::PageSpec;
     
     sub match_title ($$;@) {
    diff --git a/IkiWiki/Setup.pm b/IkiWiki/Setup.pm
    index 8a25ecc..e4d50c9 100644
    --- a/IkiWiki/Setup.pm
    +++ b/IkiWiki/Setup.pm
    @@ -51,7 +51,13 @@ sub merge ($) {
     					$config{$c}=$setup{$c};
     				}
     				else {
    -					$config{$c}=[map { IkiWiki::possibly_foolish_untaint($_) } @{$setup{$c}}]
    +					$config{$c}=[map {
    +						if(ref $_ eq 'HASH') {
    +							$_
    +						} else {
    +							IkiWiki::possibly_foolish_untaint($_)
    +						}
    +					} @{$setup{$c}}];
     				}
     			}
     			elsif (ref $setup{$c} eq 'HASH') {
    diff --git a/doc/ikiwiki/directive/meta.mdwn b/doc/ikiwiki/directive/meta.mdwn
    index 000f461..8d34ee4 100644
    --- a/doc/ikiwiki/directive/meta.mdwn
    +++ b/doc/ikiwiki/directive/meta.mdwn
    @@ -12,6 +12,16 @@ 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 `&quot;` and so on.
     
    +You can also define site-wide defaults for meta values by including them
    +in your setup file. The key used is `meta_defaults` and the value is a list
    +of hashes, one per meta directive. e.g.:
    +
    +	meta_defaults = [
    +		{ copyright => "Copyright 2007 by Joey Hess" },
    +		{ license   => "GPL v2+" },
    +		{ link => "somepage", rel => "site entrypoint", },
    +	],
    +
     Supported fields:
     
     * title

-- [[Jon]]