functions.opengraph.php

<?php
/**
 * Open Graph Tags
 *
 * Add Open Graph tags so that Facebook (and any other service that supports them)
 * can crawl the site better and we provide a better sharing experience.
 *
 * @link http://ogp.me/
 * @link http://developers.facebook.com/docs/opengraph/
 */
add_action( 'wp_head', 'jetpack_og_tags' );

function jetpack_og_tags() {
	if ( false === apply_filters( 'jetpack_enable_opengraph', true ) ) {
		_deprecated_function( 'jetpack_enable_opengraph', '2.0.3', 'jetpack_enable_open_graph' );
		return;
	}

	// Disable the widont filter on WP.com to avoid stray &nbsps
	$disable_widont = remove_filter( 'the_title', 'widont' );

	$og_output = "\n<!-- Jetpack Open Graph Tags -->\n";
	$tags = array();

	$image_width        = absint( apply_filters( 'jetpack_open_graph_image_width', 200 ) );
	$image_height       = absint( apply_filters( 'jetpack_open_graph_image_height', 200 ) );
	$description_length = 197;

	if ( is_home() || is_front_page() ) {
		$site_type              = get_option( 'open_graph_protocol_site_type' );
		$tags['og:type']        = ! empty( $site_type ) ? $site_type : 'website';
		$tags['og:title']       = get_bloginfo( 'name' );
		$tags['og:description'] = get_bloginfo( 'description' );

		$front_page_id = get_option( 'page_for_posts' );
		if ( $front_page_id && is_home() )
			$tags['og:url'] = get_permalink( $front_page_id );
		else
			$tags['og:url'] = home_url( '/' );

		// Associate a blog's root path with one or more Facebook accounts
		$facebook_admins = get_option( 'facebook_admins' );
		if ( ! empty( $facebook_admins ) )
			$tags['fb:admins'] = $facebook_admins;

	} else if ( is_author() ) {
		$tags['og:type'] = 'profile';

		$author = get_queried_object();

		$tags['og:title']           = $author->display_name;
		if ( ! empty( $author->user_url ) ) {
			$tags['og:url']     = $author->user_url;
		} else {
			$tags['og:url']     = get_author_posts_url( $author->ID );
		}
		$tags['og:description']     = $author->description;
		$tags['profile:first_name'] = get_the_author_meta( 'first_name', $author->ID );
		$tags['profile:last_name']  = get_the_author_meta( 'last_name', $author->ID );

	} else if ( is_singular() ) {
		global $post;
		$data = $post; // so that we don't accidentally explode the global

		$tags['og:type']        = 'article';
		$tags['og:title']       = empty( $data->post_title ) ? ' ' : wp_kses( $data->post_title, array() ) ;
		$tags['og:url']         = get_permalink( $data->ID );
		if ( !post_password_required() )
			$tags['og:description'] = ! empty( $data->post_excerpt ) ? preg_replace( '@https?://[\S]+@', '', strip_shortcodes( wp_kses( $data->post_excerpt, array() ) ) ): wp_trim_words( preg_replace( '@https?://[\S]+@', '', strip_shortcodes( wp_kses( $data->post_content, array() ) ) ) );
		if ( empty( $tags['og:description'] ) )
			$tags['og:description'] = __('Visit the post for more.', 'jetpack');
		$tags['article:published_time'] = date( 'c', strtotime( $data->post_date_gmt ) );
		$tags['article:modified_time'] = date( 'c', strtotime( $data->post_modified_gmt ) );
		if ( post_type_supports( get_post_type( $data ), 'author' ) && isset( $data->post_author ) ) {
			$publicize_facebook_user = get_post_meta( $data->ID, '_publicize_facebook_user', true );
			if ( ! empty( $publicize_facebook_user ) ) {
				$tags['article:author'] = esc_url( $publicize_facebook_user );
			} else {
				$tags['article:author'] = get_author_posts_url( $data->post_author );
			}
		}
	}

	// Allow plugins to inject additional template-specific open graph tags
	$tags = apply_filters( 'jetpack_open_graph_base_tags', $tags, compact( 'image_width', 'image_height' ) );

	// Re-enable widont if we had disabled it
	if ( $disable_widont )
		add_filter( 'the_title', 'widont' );

	if ( empty( $tags ) && apply_filters( 'jetpack_open_graph_return_if_empty', true ) )
		return;

	$tags['og:site_name'] = get_bloginfo( 'name' );

	if ( !post_password_required() )
		$tags['og:image']     = jetpack_og_get_image( $image_width, $image_height );

	// Facebook whines if you give it an empty title
	if ( empty( $tags['og:title'] ) )
		$tags['og:title'] = __( '(no title)', 'jetpack' );

	// Shorten the description if it's too long
	if ( isset( $tags['og:description'] ) ) {
		$tags['og:description'] = strlen( $tags['og:description'] ) > $description_length ? mb_substr( $tags['og:description'], 0, $description_length ) . '...' : $tags['og:description'];
	}

	// Add any additional tags here, or modify what we've come up with
	$tags = apply_filters( 'jetpack_open_graph_tags', $tags, compact( 'image_width', 'image_height' ) );

	// secure_urls need to go right after each og:image to work properly so we will abstract them here
	$secure = $tags['og:image:secure_url'] = ( empty( $tags['og:image:secure_url'] ) ) ? '' : $tags['og:image:secure_url'];
	unset( $tags['og:image:secure_url'] );
	$secure_image_num = 0;

	foreach ( (array) $tags as $tag_property => $tag_content ) {
		// to accommodate multiple images
		$tag_content = (array) $tag_content;
		$tag_content = array_unique( $tag_content );

		foreach ( $tag_content as $tag_content_single ) {
			if ( empty( $tag_content_single ) )
				continue; // Don't ever output empty tags
			$og_tag = sprintf( '<meta property="%s" content="%s" />', esc_attr( $tag_property ), esc_attr( $tag_content_single ) );
			$og_output .= apply_filters( 'jetpack_open_graph_output', $og_tag );
			$og_output .= "\n";

			if ( 'og:image' == $tag_property ) {
				if ( is_array( $secure ) && !empty( $secure[$secure_image_num] ) ) {
					$og_tag = sprintf( '<meta property="og:image:secure_url" content="%s" />', esc_url( $secure[ $secure_image_num ] ) );
					$og_output .= apply_filters( 'jetpack_open_graph_output', $og_tag );
					$og_output .= "\n";
				} else if ( !is_array( $secure ) && !empty( $secure ) ) {
					$og_tag = sprintf( '<meta property="og:image:secure_url" content="%s" />', esc_url( $secure ) );
					$og_output .= apply_filters( 'jetpack_open_graph_output', $og_tag );
					$og_output .= "\n";
				}
				$secure_image_num++;
			}
		}
	}
	echo $og_output;
}

function jetpack_og_get_image( $width = 200, $height = 200, $max_images = 4 ) { // Facebook requires thumbnails to be a minimum of 200x200
	$image = '';

	if ( is_singular() && !is_home() ) {
		global $post;
		$image = '';

		// Attempt to find something good for this post using our generalized PostImages code
		if ( class_exists( 'Jetpack_PostImages' ) ) {
			$post_images = Jetpack_PostImages::get_images( $post->ID, array( 'width' => $width, 'height' => $height ) );
			if ( $post_images && !is_wp_error( $post_images ) ) {
				$image = array();
				foreach ( (array) $post_images as $post_image ) {
					$image[] = $post_image['src'];
				}
			}
		}
	} else if ( is_author() ) {
		$author = get_queried_object();
		if ( function_exists( 'get_avatar_url' ) ) {
			$avatar = get_avatar_url( $author->user_email, $width );

			if ( ! empty( $avatar ) ) {
				if ( is_array( $avatar ) )
					$image = $avatar[0];
				else
					$image = $avatar;
			}
		}
		else {
			$has_filter = has_filter( 'pre_option_show_avatars', '__return_true' );
			if ( !$has_filter ) {
				add_filter( 'pre_option_show_avatars', '__return_true' );
			}
			$avatar = get_avatar( $author->user_email, $width );
			if ( !$has_filter ) {
				remove_filter( 'pre_option_show_avatars', '__return_true' );
			}

			if ( !empty( $avatar ) && !is_wp_error( $avatar ) ) {
				if ( preg_match( '/src=["\']([^"\']+)["\']/', $avatar, $matches ) );
					$image = wp_specialchars_decode( $matches[1], ENT_QUOTES );
			}
		}
	}

	if ( empty( $image ) )
		$image = array();
	else if ( !is_array( $image ) )
		$image = array( $image );

	// First fall back, blavatar
	if ( empty( $image ) && function_exists( 'blavatar_domain' ) ) {
		$blavatar_domain = blavatar_domain( site_url() );
		if ( blavatar_exists( $blavatar_domain ) )
			$image[] = blavatar_url( $blavatar_domain, 'img', $width );
	}

	// Second fall back, blank image
	if ( empty( $image ) ) {
		$image[] = apply_filters( 'jetpack_open_graph_image_default', 'https://s0.wp.com/i/blank.jpg' );
	}

	return $image;
}

/**
* @param $email
* @param $width
* @return array|bool|mixed|string
*/
function jetpack_og_get_image_gravatar( $email, $width ) {
	$image = '';
	if ( function_exists( 'get_avatar_url' ) ) {
		$avatar = get_avatar_url($email, $width);
		if ( ! empty( $avatar ) ) {
			if ( is_array( $avatar ) )
				$image = $avatar[0];
			else
				$image = $avatar;
		}
	} else {
		$has_filter = has_filter( 'pre_option_show_avatars', '__return_true' );
		if ( !$has_filter ) {
			add_filter( 'pre_option_show_avatars', '__return_true' );
		}
		$avatar = get_avatar( $email, $width );

		if ( !$has_filter ) {
			remove_filter( 'pre_option_show_avatars', '__return_true' );
		}

		if ( !empty( $avatar ) && !is_wp_error( $avatar ) ) {
			if ( preg_match( '/src=["\']([^"\']+)["\']/', $avatar, $matches ) )
				$image = wp_specialchars_decode($matches[1], ENT_QUOTES);
		}
	}

	return $image;
}