IkiWiki/Plugin/opengraph2.pm

   1 #!/usr/bin/perl
   2
   3 package IkiWiki::Plugin::opengraph2;
   4
   5 use warnings;
   6 use strict;
   7 use IkiWiki 3.00;
   8
   9 our $VERSION = '0.2.0';
  10
  11 sub import {
  12     hook(type => "preprocess", id => "opengraph2", call => \&preprocess);
  13     hook(type => "pagetemplate", id => "opengraph2", call => \&opengraph_tags);
  14 }
  15
  16 sub scrub ($$$) {
  17         if (IkiWiki::Plugin::htmlscrubber->can("sanitize")) {
  18                 return IkiWiki::Plugin::htmlscrubber::sanitize(
  19                         content => shift, page => shift, destpage => shift);
  20         }
  21         else {
  22                 return shift;
  23         }
  24 }
  25
  26 sub preprocess (@) {
  27         return "" unless @_;
  28         my %params=@_;
  29         my $key=shift;
  30         my $value=$params{$key};
  31         delete $params{$key};
  32         my $page=$params{page};
  33         delete $params{page};
  34         my $destpage=$params{destpage};
  35         delete $params{destpage};
  36         delete $params{preview};
  37
  38         eval q{use HTML::Entities};
  39         $value=decode_entities($value);
  40
  41         if ($key eq 'ogtitle') {
  42             $pagestate{$page}{opengraph2}{ogtitle}=$value;
  43         } elsif ($key eq 'ogimage') {
  44             $pagestate{$page}{opengraph2}{ogimage}=urlto($value, 'index', '1');
  45         } elsif ($key eq 'ogdesc') {
  46             $pagestate{$page}{opengraph2}{ogdesc}=$value;
  47         } elsif ($key eq 'ogtype') {
  48             $pagestate{$page}{opengraph2}{ogtype}=$value;
  49         }
  50         return "";
  51 }
  52
  53 sub opengraph_tags (@) {
  54         my %params=@_;
  55         my $page=$params{page};
  56         my $destpage=$params{destpage};
  57         my $template=$params{template};
  58
  59         my ${opengraph_title} = $pagestate{$page}{opengraph2}{ogtitle} || pagetitle(${params}{destpage}) || ${config}{'opengraph_title'};
  60         my ${opengraph_description} = $pagestate{$page}{opengraph2}{ogdesc} || ${config}{'opengraph_description'};
  61         my ${opengraph_type} = $pagestate{$page}{opengraph2}{ogtype} || ${config}{'opengraph_type'};
  62         my ${opengraph_image} = $pagestate{$page}{opengraph2}{ogimage} || ${config}{'opengraph_image'};
  63         my ${opengraph_url} = urlto(${params}{destpage}, 'index', '1') || ${config}{'opengraph_url'};
  64
  65         my ${opengraph_tag_title} = '<meta property="og:title" content="'.${opengraph_title}.'" />';
  66         my ${opengraph_tag_description} = '<meta property="og:description" content="'.${opengraph_description}.'" />';
  67         my ${opengraph_tag_type} = '<meta property="og:type" content="'.${opengraph_type}.'" />';
  68         my ${opengraph_tag_image} = '<meta property="og:image" content="'.${opengraph_image}.'" />';
  69         my ${opengraph_tag_url} = '<meta property="og:url" content="'.${opengraph_url}.'" />';
  70
  71         if (exists $pagestate{$page}{opengraph2} && $template->query(name => "meta")) {
  72             my %seen;
  73             $template->param(meta => join("\n",grep { (! $seen{$_}) && ($seen{$_}=1) } ${opengraph_tag_title},
  74                                           ,"\n",${opengraph_tag_description},
  75                                           ,"\n",${opengraph_tag_type},
  76                                           ,"\n",${opengraph_tag_image},
  77                                           ,"\n",${opengraph_tag_url}));
  78         }
  79
  80 }
  81
  82 1;
  83
  84 __END__
  85
  86 =head1 NAME
  87
  88 IkiWiki::Plugin::opengraph2 - Adds Open Graph tags on the html head
  89
  90 =head1 DESCRIPTION
  91
  92 This plugin implements the Open Graph tags in the head of the hmtl for pages that have an opengraph2 directive. For more information on what is Open Graph, visit
  93 <https://en.wikipedia.org/wiki/Open_Graph>. To test your site against the
  94 Open Graph rules, use the tool available on
  95 <https://developers.facebook.com/tools/debug/og/object/>.
  96
  97 =head1 INSTALLATION
  98
  99 Put F<opengraph2.pm> in F<$HOME/.ikiwiki/IkiWiki/Plugin/> or elsewhere in
 100 your C<@INC> path. Or read <http://ikiwiki.info/plugins/install/>.
 101
 102 =head1 CONFIGURATION
 103
 104 Add to the configuration in your F<blog.setup> file.
 105
 106         ## opengraph2 plugin
 107         # For more information, see
 108         # <https://en.wikipedia.org/wiki/Open_Graph#Open_Graph_protocol>.
 109         # Default values for <http://ikiwiki.info>
 110         # obtained from <https://developers.facebook.com/tools/debug/og/object/>
 111         # meta property="og:title"
 112         opengraph_title: "ikiwiki"
 113         # meta property="og:type"
 114         opengraph_type: "website"
 115         # meta property="og:url"
 116         opengraph_url: "http://ikiwiki.info/"
 117         # meta property="og:image"
 118         opengraph_image: "http://ikiwiki.info/logo/ikiwiki.png"
 119         # meta property="og:description"
 120         opengraph_description: "Ikiwiki is a wiki compiler."
 121
 122 Add C<meta> and C<opengraph2> to the list of plugins:
 123
 124         add_plugins => [qw{goodstuff opengraph2}],
 125
 126 Use opengraph2 directives ogdesc, ogtype, ogtitle or ogimage to set a page as needing Open Graph headers. Values from the config will be used for any omitted directives.
 127
 128 =head1 TEMPLATES
 129
 130 Meta tags will show where the meta plugin has been configured to place them.
 131
 132 =head1 BUGS AND LIMITATIONS
 133
 134 =head1 LICENSE AND COPYRIGHT
 135
 136 Copyleft (.) 2022 Frederik Vanrenterghem
 137 This program is free software: you can redistribute it and/or modify
 138 it under the terms of the GNU General Public License as published by
 139 the Free Software Foundation, either version 3 of the License, or
 140 (at your option) any later version.
 141 This program is distributed in the hope that it will be useful,
 142 but WITHOUT ANY WARRANTY; without even the implied warranty of
 143 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 144 GNU General Public License for more details.
 145 You should have received a copy of the GNU General Public License
 146 along with this program. If not, see <http://www.gnu.org/licenses/>.
 147
 148 =head1 SEE ALSO
 149
 150 =over 4
 151
 152 =item https://ikiwiki.info/plugins/contrib/opengraph/
 153
 154 =item https://en.wikipedia.org/wiki/Open_Graph
 155
 156 =back