opengraph / opengraph.php

opengraph.php in Open Graph 1.3, at opengraph.php

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1	<?php
2	/*
3	Plugin Name: Open Graph
4	Plugin URI: http://wordpress.org/extend/plugins/opengraph
5	Description: Adds Open Graph metadata to your pages
6	Author: Will Norris
7	Author URI: http://willnorris.com/
8	Version: 1.3
9	License: Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0.html)
10	Text Domain: opengraph
11	*/
12
13
14	define('OPENGRAPH_PREFIX_URI', 'http://ogp.me/ns#');
15	$opengraph_prefix_set = false;
16
17
18	/**
19	* Add Open Graph XML prefix to <html> element.
20	*
21	* @uses apply_filters calls 'opengraph_prefixes' filter on RDFa prefix array
22	*/
23	function opengraph_add_prefix( $output ) {
24	$prefixes = array(
25	'og' => OPENGRAPH_PREFIX_URI
26	);
27	$prefixes = apply_filters('opengraph_prefixes', $prefixes);
28
29	$prefix_str = '';
30	foreach( $prefixes as $k => $v ) {
31	$prefix_str .= $k . ': ' . $v . ' ';
32	}
33	$prefix_str = trim($prefix_str);
34
35	if (preg_match('/(prefix\s=\s[\"\|\'])/i', $output)) {
36	$output = preg_replace('/(prefix\s=\s[\"\|\'])/i', '${1}' . $prefix_str, $output);
37	} else {
38	$output .= ' prefix="' . $prefix_str . '"';
39	}
40	return $output;
41	}
42	add_filter('language_attributes', 'opengraph_add_prefix');
43
44
45	/**
46	* Get the Open Graph metadata for the current page.
47	*
48	* @uses apply_filters() Calls 'opengraph_{$name}' for each property name
49	* @uses apply_filters() Calls 'opengraph_metadata' before returning metadata array
50	*/
51	function opengraph_metadata() {
52	$metadata = array();
53
54	// defualt properties defined at http://ogp.me/
55	$properties = array(
56	// required
57	'title', 'type', 'image', 'url',
58
59	// optional
60	'audio', 'description', 'determiner', 'locale', 'site_name', 'video',
61	);
62
63	foreach ($properties as $property) {
64	$filter = 'opengraph_' . $property;
65	$metadata["og:$property"] = apply_filters($filter, '');
66	}
67	return apply_filters('opengraph_metadata', $metadata);
68	}
69
70
71	/**
72	* Register filters for default Open Graph metadata.
73	*/
74	function opengraph_default_metadata() {
75	add_filter('opengraph_title', 'opengraph_default_title', 5);
76	add_filter('opengraph_type', 'opengraph_default_type', 5);
77	add_filter('opengraph_image', 'opengraph_default_image', 5);
78	add_filter('opengraph_url', 'opengraph_default_url', 5);
79
80	add_filter('opengraph_description', 'opengraph_default_description', 5);
81	add_filter('opengraph_locale', 'opengraph_default_locale', 5);
82	add_filter('opengraph_site_name', 'opengraph_default_sitename', 5);
83	}
84	add_filter('wp', 'opengraph_default_metadata');
85
86
87	/**
88	* Default title property, using the page title.
89	*/
90	function opengraph_default_title( $title ) {
91	if ( is_singular() && empty($title) ) {
92	global $post;
93	$title = $post->post_title;
94	}
95	return $title;
96	}
97
98
99	/**
100	* Default type property.
101	*/
102	function opengraph_default_type( $type ) {
103	if ( is_singular( array('post', 'page', 'aside', 'status') ) && empty($type) ) {
104	$type = 'article';
105	} elseif ( empty($type) ) {
106	$type = 'blog';
107	}
108	return $type;
109	}
110
111
112	/**
113	* Default image property, using the post-thumbnail.
114	*/
115	function opengraph_default_image( $image ) {
116	global $post;
117	if ( function_exists('has_post_thumbnail') ) {
118	if ( is_singular() && empty($image) && has_post_thumbnail($post->ID) ) {
119	$thumbnail = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'post-thumbnail');
120	if ($thumbnail) {
121	$image = $thumbnail[0];
122	}
123	}
124	}
125	return $image;
126	}
127
128
129	/**
130	* Default url property, using the permalink for the page.
131	*/
132	function opengraph_default_url( $url ) {
133	if ( is_singular() && empty($url) ) $url = get_permalink();
134	return $url;
135	}
136
137
138	/**
139	* Default site_name property, using the bloginfo name.
140	*/
141	function opengraph_default_sitename( $name ) {
142	if ( empty($name) ) $name = get_bloginfo('name');
143	return $name;
144	}
145
146
147	/**
148	* Default description property, using the bloginfo description.
149	*/
150	function opengraph_default_description( $description ) {
151	if ( is_singular() && empty($description) ) {
152	if ( has_excerpt() ) {
153	$description = get_the_excerpt();
154	} else {
155	global $post;
156	$description = wp_trim_words( strip_shortcodes($post->post_content), 25, '...' );
157	}
158	} elseif ( empty($description) ) {
159	$description = get_bloginfo('description');
160	}
161	return $description;
162	}
163
164
165	/**
166	* Default locale property, using the WordPress locale.
167	*/
168	function opengraph_default_locale( $locale ) {
169	if ( empty($locale) ) $locale = get_locale();
170	return $locale;
171	}
172
173
174	/**
175	* Output Open Graph <meta> tags in the page header.
176	*/
177	function opengraph_meta_tags() {
178	$metadata = opengraph_metadata();
179	foreach ( $metadata as $key => $value ) {
180	if ( empty($key) \|\| empty($value) ) continue;
181	if ( is_array( $value ) ) {
182	foreach ( $value as $v ) {
183	echo '<meta property="' . esc_attr($key) . '" content="' . esc_attr($v) . '" />' . "\n";
184	}
185	} else {
186	echo '<meta property="' . esc_attr($key) . '" content="' . esc_attr($value) . '" />' . "\n";
187	}
188	}
189	}
190	add_action('wp_head', 'opengraph_meta_tags');
191
192