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<?php |
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/* |
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Plugin Name: Open Graph |
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Plugin URI: http://wordpress.org/extend/plugins/opengraph |
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Description: Adds Open Graph metadata to your pages |
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Author: Will Norris |
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Author URI: http://willnorris.com/ |
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Version: 1.2 |
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License: Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0.html) |
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Text Domain: opengraph |
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*/ |
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|
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|
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define('OPENGRAPH_PREFIX_URI', 'http://ogp.me/ns#'); |
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$opengraph_prefix_set = false; |
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|
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|
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/** |
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* Add Open Graph XML prefix to <html> element. |
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*/ |
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function opengraph_add_prefix( $output ) { |
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global $opengraph_prefix_set; |
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$opengraph_prefix_set = true; |
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|
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if (preg_match('/(prefix\s*=\s*[\"|\'])/i', $output)) { |
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$output = preg_replace('/(prefix\s*=\s*[\"|\'])/i', '${1}og: ' . esc_attr(OPENGRAPH_PREFIX_URI) . ' ', $output); |
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} else { |
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$output .= ' prefix="og: ' . esc_attr(OPENGRAPH_PREFIX_URI) . '"'; |
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} |
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return $output; |
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} |
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add_filter('language_attributes', 'opengraph_add_prefix'); |
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|
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|
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/** |
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* Get the Open Graph metadata for the current page. |
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* |
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* @uses apply_filters() Calls 'opengraph_{$name}' for each property name |
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* @uses apply_filters() Calls 'opengraph_metadata' before returning metadata array |
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*/ |
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function opengraph_metadata() { |
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$metadata = array(); |
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|
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// defualt properties defined at http://opengraphprotocol.org/ |
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$properties = array( |
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// required |
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'title', 'type', 'image', 'url', |
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|
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// optional |
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'site_name', 'description', |
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|
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// location |
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'longitude', 'latitude', 'street-address', 'locality', 'region', |
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'postal-code', 'country-name', |
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|
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// contact |
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'email', 'phone_number', 'fax_number', |
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); |
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|
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foreach ($properties as $property) { |
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$filter = 'opengraph_' . $property; |
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$metadata["og:$property"] = apply_filters($filter, ''); |
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} |
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|
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return apply_filters('opengraph_metadata', $metadata); |
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} |
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|
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|
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/** |
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* Register filters for default Open Graph metadata. |
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*/ |
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function opengraph_default_metadata() { |
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add_filter('opengraph_title', 'opengraph_default_title', 5); |
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add_filter('opengraph_type', 'opengraph_default_type', 5); |
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add_filter('opengraph_image', 'opengraph_default_image', 5); |
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add_filter('opengraph_url', 'opengraph_default_url', 5); |
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|
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add_filter('opengraph_site_name', 'opengraph_default_sitename', 5); |
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add_filter('opengraph_description', 'opengraph_default_description', 5); |
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} |
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add_filter('wp', 'opengraph_default_metadata'); |
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|
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|
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/** |
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* Default title property, using the page title. |
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*/ |
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function opengraph_default_title( $title ) { |
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if ( is_singular() && empty($title) ) { |
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global $post; |
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$title = $post->post_title; |
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} |
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|
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return $title; |
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} |
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|
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|
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/** |
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* Default type property. |
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*/ |
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function opengraph_default_type( $type ) { |
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if ( empty($type) ) $type = 'blog'; |
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return $type; |
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} |
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|
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|
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/** |
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* Default image property, using the post-thumbnail. |
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*/ |
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function opengraph_default_image( $image ) { |
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global $post; |
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if ( function_exists('has_post_thumbnail') ) { |
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if ( is_singular() && empty($image) && has_post_thumbnail($post->ID) ) { |
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$thumbnail = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'post-thumbnail'); |
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if ($thumbnail) { |
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$image = $thumbnail[0]; |
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} |
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} |
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} |
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|
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return $image; |
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} |
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|
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|
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/** |
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* Default url property, using the permalink for the page. |
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*/ |
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function opengraph_default_url( $url ) { |
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if ( empty($url) ) $url = get_permalink(); |
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return $url; |
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} |
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|
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|
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/** |
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* Default site_name property, using the bloginfo name. |
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*/ |
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function opengraph_default_sitename( $name ) { |
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if ( empty($name) ) $name = get_bloginfo('name'); |
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return $name; |
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} |
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|
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|
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/** |
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* Default description property, using the bloginfo description. |
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*/ |
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function opengraph_default_description( $description ) { |
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if ( empty($description) ) $description = get_bloginfo('description'); |
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return $description; |
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} |
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|
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|
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/** |
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* Output Open Graph <meta> tags in the page header. |
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*/ |
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function opengraph_meta_tags() { |
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global $opengraph_prefix_set; |
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|
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$prefix = ''; |
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if ( !$opengraph_prefix_set ) { |
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$prefix = 'prefix="og: ' . esc_attr(OPENGRAPH_PREFIX_URI) . '" '; |
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} |
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|
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$metadata = opengraph_metadata(); |
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foreach ( $metadata as $key => $value ) { |
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if ( empty($key) || empty($value) ) continue; |
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echo '<meta ' . $prefix . 'property="' . esc_attr($key) . '" content="' . esc_attr($value) . '" />' . "\n"; |
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} |
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} |
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add_action('wp_head', 'opengraph_meta_tags'); |
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|
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