Esempio n. 1
0
/**
 * Generates Opengraph metadata.
 *
 * Currently for:
 * - home page
 * - author archive
 * - content
 */
function amt_add_opengraph_metadata_head($post, $attachments, $embedded_media, $options)
{
    if (apply_filters('amt_exclude_opengraph_metadata', false)) {
        return array();
    }
    $do_auto_opengraph = $options["auto_opengraph"] == "1" ? true : false;
    if (!$do_auto_opengraph) {
        return array();
    }
    $metadata_arr = array();
    // fb:app_id & fb:admins
    // We currently let users add the full meta tags for fb:app_id and fb:admins in the site wide meta tags box.
    // fb:app_id appears everywhere
    //if ( ! empty($options['social_main_facebook_app_id']) ) {
    //    $metadata_arr[] = '<meta property="fb:app_id" content="' . esc_attr( $options['social_main_facebook_app_id'] ) . '" />';
    //}
    // fb:admins appear everywhere
    //if ( ! empty($options['social_main_facebook_admins']) ) {
    //    $fb_admins_arr = explode(',', $options['social_main_facebook_admins']);
    //    foreach ( $fb_admins_arr as $fb_admin ) {
    //        $metadata_arr[] = '<meta property="fb:admins" content="' . esc_attr( trim($fb_admin) ) . '" />';
    //    }
    //}
    // no publisher meta tag for facebook, unless it is content
    // Custom content override
    if (amt_is_custom($post, $options)) {
        // Return metadata with:
        // add_filter( 'amt_custom_metadata_opengraph', 'my_function', 10, 5 );
        // Return an array of meta tags. Array item format: ['key_can_be_whatever'] = '<meta name="foo" content="bar" />'
        $metadata_arr = apply_filters('amt_custom_metadata_opengraph', $metadata_arr, $post, $options, $attachments, $embedded_media);
        // Default front page displaying the latest posts
    } elseif (amt_is_default_front_page()) {
        // Type
        $metadata_arr[] = '<meta property="og:type" content="website" />';
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title - Note: Contains multipage information
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL - Note: different method to get the permalink on paged archives
        if (is_paged()) {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_pagenum_link(get_query_var('paged'))) . '" />';
        } else {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(trailingslashit(get_bloginfo('url'))) . '" />';
        }
        // Site description - Note: Contains multipage information through amt_process_paged()
        $site_description = amt_get_site_description($options);
        if (empty($site_description)) {
            $site_description = get_bloginfo('description');
        }
        if (!empty($site_description)) {
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($site_description)) . '" />';
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_site($options))) . '" />';
        // Site Image
        // Use the default image, if one has been set.
        $image_data = amt_get_default_image_data();
        if (!empty($image_data)) {
            $image_size = apply_filters('amt_image_size_index', 'full');
            $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
            if (!empty($image_meta_tags)) {
                $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
            }
        }
        // Front page using a static page
        // Note: might also contain a listing of posts which may be paged, so use amt_process_paged()
    } elseif (amt_is_static_front_page()) {
        // Type
        if ($options['author_profile_source'] == 'frontpage') {
            // The front page is treated as the profile page.
            $metadata_arr[] = '<meta property="og:type" content="profile" />';
        } else {
            $metadata_arr[] = '<meta property="og:type" content="website" />';
        }
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title - Note: Contains multipage information
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL - Note: different method to get the permalink on paged archives
        if (is_paged()) {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_pagenum_link(get_query_var('paged'))) . '" />';
        } else {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(trailingslashit(get_bloginfo('url'))) . '" />';
        }
        // Site Description - Note: Contains multipage information through amt_process_paged()
        $content_desc = amt_get_content_description($post);
        if (!empty($content_desc)) {
            // Use the pages custom description
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($content_desc)) . '" />';
        } elseif (get_bloginfo('description')) {
            // Alternatively use the blog's description
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged(get_bloginfo('description'))) . '" />';
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_content($options, $post))) . '" />';
        // Site Image
        // First check if a global image override URL has been entered.
        // If yes, use this image URL and override all other images.
        $image_data = amt_get_image_attributes_array(amt_get_post_meta_image_url($post->ID));
        if (!empty($image_data)) {
            $image_size = apply_filters('amt_image_size_index', 'full');
            $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
            if (!empty($image_meta_tags)) {
                $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
            }
            //$global_image_override_url = amt_get_post_meta_image_url($post->ID);
            //if ( ! empty( $global_image_override_url ) ) {
            //    $metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $global_image_override_url ) . '" />';
            //    if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
            //        $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $global_image_override_url ) ) . '" />';
            //    }
            // Then try the featured image, if exists.
        } elseif (function_exists('has_post_thumbnail') && has_post_thumbnail($post->ID)) {
            // Allow filtering of the image size.
            $image_size = apply_filters('amt_image_size_index', 'full');
            $metadata_arr = array_merge($metadata_arr, amt_get_opengraph_image_metatags($options, get_post_thumbnail_id($post->ID), $size = $image_size));
        } else {
            // Use the default image, if one has been set.
            $image_data = amt_get_default_image_data();
            if (!empty($image_data)) {
                $image_size = apply_filters('amt_image_size_index', 'full');
                $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
                if (!empty($image_meta_tags)) {
                    $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
                }
            }
            // Alternatively, use default image
            //$metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $options["default_image_url"] ) . '" />';
            //if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
            //    $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $options["default_image_url"] ) ) . '" />';
            //}
        }
        // Profile data (only if the front page has been set as the source of profile.)
        if ($options['author_profile_source'] == 'frontpage') {
            // Profile first and last name
            $last_name = get_the_author_meta('last_name', $post->post_author);
            if (!empty($last_name)) {
                $metadata_arr[] = '<meta property="profile:last_name" content="' . esc_attr($last_name) . '" />';
            }
            $first_name = get_the_author_meta('first_name', $post->post_author);
            if (!empty($first_name)) {
                $metadata_arr[] = '<meta property="profile:first_name" content="' . esc_attr($first_name) . '" />';
            }
        }
        // The posts index page - a static page displaying the latest posts
    } elseif (amt_is_static_home()) {
        // Type
        $metadata_arr[] = '<meta property="og:type" content="website" />';
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title - Note: Contains multipage information
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL - Note: different method to get the permalink on paged archives
        if (is_paged()) {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_pagenum_link(get_query_var('paged'))) . '" />';
        } else {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_permalink($post->ID)) . '" />';
        }
        // Site Description - Note: Contains multipage information through amt_process_paged()
        $content_desc = amt_get_content_description($post);
        if (!empty($content_desc)) {
            // Use the pages custom description
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($content_desc)) . '" />';
        } elseif (get_bloginfo('description')) {
            // Alternatively use a generic description
            $metadata_arr[] = '<meta property="og:description" content="' . amt_process_paged("An index of the latest content.") . '" />';
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_content($options, $post))) . '" />';
        // Site Image
        // First check if a global image override URL has been entered.
        // If yes, use this image URL and override all other images.
        $image_data = amt_get_image_attributes_array(amt_get_post_meta_image_url($post->ID));
        if (!empty($image_data)) {
            $image_size = apply_filters('amt_image_size_index', 'full');
            $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
            if (!empty($image_meta_tags)) {
                $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
            }
            //$global_image_override_url = amt_get_post_meta_image_url($post->ID);
            //if ( ! empty( $global_image_override_url ) ) {
            //    $metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $global_image_override_url ) . '" />';
            //    if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
            //        $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $global_image_override_url ) ) . '" />';
            //    }
            // Then try the featured image, if exists.
        } elseif (function_exists('has_post_thumbnail') && has_post_thumbnail($post->ID)) {
            // Allow filtering of the image size.
            $image_size = apply_filters('amt_image_size_index', 'full');
            $metadata_arr = array_merge($metadata_arr, amt_get_opengraph_image_metatags($options, get_post_thumbnail_id($post->ID), $size = $image_size));
        } else {
            // Use the default image, if one has been set.
            $image_data = amt_get_default_image_data();
            if (!empty($image_data)) {
                $image_size = apply_filters('amt_image_size_index', 'full');
                $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
                if (!empty($image_meta_tags)) {
                    $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
                }
            }
            // Alternatively, use default image
            //$metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $options["default_image_url"] ) . '" />';
            //if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
            //    $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $options["default_image_url"] ) ) . '" />';
            //}
        }
        // Category, Tag, Taxonomy archives
        // Note: product groups should pass the is_tax() validation, so no need for
        // amt_is_product_group(). We do not support other product groups.
        // amt_is_product_group() is used below to set the og:type to product.group.
    } elseif (is_category() || is_tag() || is_tax()) {
        // Taxonomy term object.
        // When viewing taxonomy archives, the $post object is the taxonomy term object. Check with: var_dump($post);
        $tax_term_object = $post;
        //var_dump($tax_term_object);
        // Type
        // In case of a product group taxonomy, we set the og:type to product.group
        if (amt_is_product_group()) {
            $metadata_arr[] = '<meta property="og:type" content="product.group" />';
        } else {
            $metadata_arr[] = '<meta property="og:type" content="website" />';
        }
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title - Note: Contains multipage information
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL - Note: different method to get the permalink on paged archives
        $url = get_term_link($tax_term_object);
        if (is_paged()) {
            $url = trailingslashit($url) . get_query_var('paged') . '/';
        }
        $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw($url) . '" />';
        // Description
        // If set, the description of the custom taxonomy term is used in the 'description' metatag.
        // Otherwise, a generic description is used.
        // Here we sanitize the provided description for safety
        $description_content = sanitize_text_field(amt_sanitize_description(term_description($tax_term_object->term_id, $tax_term_object->taxonomy)));
        // Note: Contains multipage information through amt_process_paged()
        if (empty($description_content)) {
            // Add a filtered generic description.
            // Filter name
            if (is_category()) {
                $generic_description = apply_filters('amt_generic_description_category_archive', __('Content filed under the %s category.', 'add-meta-tags'));
            } elseif (is_tag()) {
                $generic_description = apply_filters('amt_generic_description_tag_archive', __('Content tagged with %s.', 'add-meta-tags'));
            } elseif (is_tax()) {
                // Construct the filter name. Template: ``amt_generic_description_TAXONOMYSLUG_archive``
                $taxonomy_description_filter_name = sprintf('amt_generic_description_%s_archive', $tax_term_object->taxonomy);
                // var_dump($taxonomy_description_filter_name);
                // Generic description
                $generic_description = apply_filters($taxonomy_description_filter_name, __('Content filed under the %s taxonomy.', 'add-meta-tags'));
            }
            // Final generic description
            $generic_description = sprintf($generic_description, single_term_title($prefix = '', $display = false));
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($generic_description)) . '" />';
        } else {
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($description_content)) . '" />';
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_site($options))) . '" />';
        // Image
        // Use an image from the 'Global image override' field.
        // Otherwise, use a user defined image via filter.
        // Otherwise use default image.
        $image_data = amt_get_image_attributes_array(amt_get_term_meta_image_url($tax_term_object->term_id));
        if (!empty($image_data)) {
            $image_size = apply_filters('amt_image_size_index', 'full');
            $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
            if (!empty($image_meta_tags)) {
                $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
            }
        } else {
            // First filter using a term/taxonomy agnostic filter name.
            $taxonomy_image_url = apply_filters('amt_taxonomy_force_image_url', '', $tax_term_object);
            if (empty($taxonomy_image_url)) {
                // Second filter (term/taxonomy dependent).
                // Construct the filter name. Template: ``amt_taxonomy_image_url_TAXONOMYSLUG_TERMSLUG``
                $taxonomy_image_url_filter_name = sprintf('amt_taxonomy_image_url_%s_%s', $tax_term_object->taxonomy, $tax_term_object->slug);
                //var_dump($taxonomy_image_url_filter_name);
                // The default image, if set, is used by default.
                $taxonomy_image_url = apply_filters($taxonomy_image_url_filter_name, $options["default_image_url"]);
            }
            if (!empty($taxonomy_image_url)) {
                $image_data = amt_get_image_attributes_array($taxonomy_image_url);
                if (!empty($image_data)) {
                    $image_size = apply_filters('amt_image_size_index', 'full');
                    $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
                    if (!empty($image_meta_tags)) {
                        $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
                    }
                }
                //$metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $taxonomy_image_url ) . '" />';
                //if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
                //    $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $taxonomy_image_url ) ) . '" />';
                //}
            }
        }
        // Author archive. First page is considered a profile page.
    } elseif (is_author()) {
        // Author object
        // NOTE: Inside the author archives `$post->post_author` does not contain the author object.
        // In this case the $post (get_queried_object()) contains the author object itself.
        // We also can get the author object with the following code. Slug is what WP uses to construct urls.
        // $author = get_user_by( 'slug', get_query_var( 'author_name' ) );
        // Also, ``get_the_author_meta('....', $author)`` returns nothing under author archives.
        // Access user meta with:  $author->description, $author->user_email, etc
        // $author = get_queried_object();
        $author = $post;
        // Type
        if (!is_paged() && $options['author_profile_source'] == 'default') {
            // We treat the first page of the archive as a profile, only if
            // the profile source has been set to 'default'
            $metadata_arr[] = '<meta property="og:type" content="profile" />';
        } else {
            $metadata_arr[] = '<meta property="og:type" content="website" />';
        }
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title - Note: Contains multipage information
        //if ( ! is_paged() ) {
        //    // We treat the first page of the archive as a profile
        //    $metadata_arr[] = '<meta property="og:title" content="' . esc_attr( $author->display_name ) . ' profile page" />';
        //} else {
        //    $metadata_arr[] = '<meta property="og:title" content="' . esc_attr( amt_process_paged( "Content published by " . $author->display_name ) ) . '" />';
        //}
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . ' profile page" />';
        // URL - Note: different method to get the permalink on paged archives
        // If a Facebook author profile URL has been provided, it has priority,
        // Otherwise fall back to the WordPress author archive.
        $fb_author_url = $author->amt_facebook_author_profile_url;
        if (!empty($fb_author_url)) {
            $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw($fb_author_url, array('http', 'https')) . '" />';
        } else {
            if (is_paged()) {
                $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_pagenum_link(get_query_var('paged'))) . '" />';
            } else {
                $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_author_posts_url($author->ID)) . '" />';
                // The following makes no sense here. 'get_author_posts_url( $author->ID )' will do in all cases.
                //$metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw( amt_get_local_author_profile_url( $author->ID, $options ) ) . '" />';
            }
        }
        // description - Note: Contains multipage information through amt_process_paged()
        if (is_paged()) {
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged("Content published by " . $author->display_name)) . '" />';
        } else {
            // Here we sanitize the provided description for safety
            // We treat the first page of the archive as a profile
            $author_description = sanitize_text_field(amt_sanitize_description($author->description));
            if (empty($author_description)) {
                $metadata_arr[] = '<meta property="og:description" content="' . esc_attr("Content published by " . $author->display_name) . '" />';
            } else {
                $metadata_arr[] = '<meta property="og:description" content="' . esc_attr($author_description) . '" />';
            }
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_site($options))) . '" />';
        // Profile Image
        // First use the global image override URL
        $image_data = amt_get_image_attributes_array(amt_get_user_meta_image_url($author->ID));
        if (!empty($image_data)) {
            $image_size = apply_filters('amt_image_size_index', 'full');
            $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
            if (!empty($image_meta_tags)) {
                $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
            }
        } else {
            $author_email = sanitize_email($author->user_email);
            $avatar_size = apply_filters('amt_avatar_size', 128);
            $avatar_url = '';
            // First try to get the avatar link by using get_avatar().
            // Important: for this to work the "Show Avatars" option should be enabled in Settings > Discussion.
            $avatar_img = get_avatar(get_the_author_meta('ID', $author->ID), $avatar_size, '', get_the_author_meta('display_name', $author->ID));
            if (!empty($avatar_img)) {
                if (preg_match("#src=['\"]([^'\"]+)['\"]#", $avatar_img, $matches)) {
                    $avatar_url = $matches[1];
                }
            } elseif (!empty($author_email)) {
                // If the user has provided an email, we use it to construct a gravatar link.
                $avatar_url = "http://www.gravatar.com/avatar/" . md5($author_email) . "?s=" . $avatar_size;
            }
            if (!empty($avatar_url)) {
                //$avatar_url = html_entity_decode($avatar_url, ENT_NOQUOTES, 'UTF-8');
                $metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw($avatar_url) . '" />';
                // Add an og:imagesecure_url if the image URL uses HTTPS
                if (strpos($avatar_url, 'https://') !== false) {
                    $metadata_arr[] = '<meta property="og:imagesecure_url" content="' . esc_url_raw($avatar_url) . '" />';
                }
                if (apply_filters('amt_extended_image_tags', true)) {
                    $metadata_arr[] = '<meta property="og:image:width" content="' . esc_attr($avatar_size) . '" />';
                    $metadata_arr[] = '<meta property="og:image:height" content="' . esc_attr($avatar_size) . '" />';
                    // Since we do not have a way to determine the image type, the following meta tag is commented out
                    // TODO: make a function that detects the image type from the file extension (if a file extension is available)
                    //$metadata_arr[] = '<meta property="og:image:type" content="image/jpeg" />';
                }
            }
        }
        // Profile data (only on the 1st page of the archive)
        if (!is_paged() && $options['author_profile_source'] == 'default') {
            // Profile first and last name
            $last_name = $author->last_name;
            if (!empty($last_name)) {
                $metadata_arr[] = '<meta property="profile:last_name" content="' . esc_attr($last_name) . '" />';
            }
            $first_name = $author->first_name;
            if (!empty($first_name)) {
                $metadata_arr[] = '<meta property="profile:first_name" content="' . esc_attr($first_name) . '" />';
            }
        }
        // Custom Post Type archives
    } elseif (is_post_type_archive()) {
        // Custom post type object.
        // When viewing custom post type archives, the $post object is the custom post type object. Check with: var_dump($post);
        $post_type_object = $post;
        //var_dump($post_type_object);
        // Type
        $metadata_arr[] = '<meta property="og:type" content="website" />';
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title - Note: Contains multipage information
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL - Note: different method to get the permalink on paged archives
        $url = get_post_type_archive_link($post_type_object->name);
        if (is_paged()) {
            $url = trailingslashit($url) . get_query_var('paged') . '/';
        }
        $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw($url) . '" />';
        // Description
        // Note: Contains multipage information through amt_process_paged()
        // Add a filtered generic description.
        // Construct the filter name. Template: ``amt_generic_description_posttype_POSTTYPESLUG_archive``
        $custom_post_type_description_filter_name = sprintf('amt_generic_description_posttype_%s_archive', $post_type_object->name);
        // var_dump($custom_post_type_description_filter_name);
        // Generic description
        $generic_description = apply_filters($custom_post_type_description_filter_name, __('%s archive.', 'add-meta-tags'));
        // Final generic description
        $generic_description = sprintf($generic_description, post_type_archive_title($prefix = '', $display = false));
        $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($generic_description)) . '" />';
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_site($options))) . '" />';
        // Image
        // Use a user defined image via filter. Otherwise use default image.
        // First filter using a term/taxonomy agnostic filter name.
        $posttype_image_url = apply_filters('amt_posttype_force_image_url', '', $post_type_object);
        if (empty($posttype_image_url)) {
            // Second filter (post type dependent).
            // Construct the filter name. Template: ``amt_posttype_image_url_POSTTYPESLUG``
            $posttype_image_url_filter_name = sprintf('amt_posttype_image_url_%s', $post_type_object->name);
            //var_dump($posttype_image_url_filter_name);
            // The default image, if set, is used by default.
            $posttype_image_url = apply_filters($posttype_image_url_filter_name, $options["default_image_url"]);
        }
        if (!empty($posttype_image_url)) {
            $image_data = amt_get_image_attributes_array($posttype_image_url);
            if (!empty($image_data)) {
                $image_size = apply_filters('amt_image_size_index', 'full');
                $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
                if (!empty($image_meta_tags)) {
                    $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
                }
            }
            //$metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $posttype_image_url ) . '" />';
            //if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
            //    $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $posttype_image_url ) ) . '" />';
            //}
        }
        // Attachments
    } elseif (is_attachment()) {
        $mime_type = get_post_mime_type($post->ID);
        //$attachment_type = strstr( $mime_type, '/', true );
        // See why we do not use strstr(): http://www.codetrax.org/issues/1091
        $attachment_type = preg_replace('#\\/[^\\/]*$#', '', $mime_type);
        // First add metadata common to all attachment types.
        // Type
        // Note: there is no specific type for images/audio. We use article amd video
        // TODO: Check whether we could use another type specific to each attachment type.
        if ('video' == $attachment_type) {
            // video.other og:type for video attachment pages
            $og_type = 'video.other';
        } else {
            $og_type = 'article';
        }
        $og_type = apply_filters('amt_opengraph_og_type_attachment', $og_type);
        $metadata_arr[] = '<meta property="og:type" content="' . esc_attr($og_type) . '" />';
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Title
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL
        $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(get_permalink($post->ID)) . '" />';
        // Description - We use the description defined by Add-Meta-Tags
        $content_desc = amt_get_content_description($post);
        if (!empty($content_desc)) {
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr($content_desc) . '" />';
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_content($options, $post))) . '" />';
        // og:updated_time
        $metadata_arr[] = '<meta property="og:updated_time" content="' . esc_attr(amt_iso8601_date($post->post_modified)) . '" />';
        // Metadata specific to each attachment type
        if ('image' == $attachment_type) {
            // Allow filtering of the image size.
            $image_size = apply_filters('amt_image_size_attachment', 'full');
            $metadata_arr = array_merge($metadata_arr, amt_get_opengraph_image_metatags($options, $post->ID, $size = $image_size));
        } elseif ('video' == $attachment_type) {
            if ($options["og_omit_video_metadata"] != "1") {
                // Video tags
                $metadata_arr[] = '<meta property="og:video" content="' . esc_url_raw(wp_get_attachment_url($post->ID)) . '" />';
                if (is_ssl() || !is_ssl() && $options["has_https_access"] == "1") {
                    $metadata_arr[] = '<meta property="og:video:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', wp_get_attachment_url($post->ID))) . '" />';
                }
                //
                //$metadata_arr[] = '<meta property="og:video:width" content="' . esc_attr( $main_size_meta[1] ) . '" />';
                //$metadata_arr[] = '<meta property="og:video:height" content="' . esc_attr( $main_size_meta[2] ) . '" />';
                $metadata_arr[] = '<meta property="og:video:type" content="' . esc_attr($mime_type) . '" />';
            }
        } elseif ('audio' == $attachment_type) {
            // Audio tags
            $metadata_arr[] = '<meta property="og:audio" content="' . esc_url_raw(wp_get_attachment_url($post->ID)) . '" />';
            if (is_ssl() || !is_ssl() && $options["has_https_access"] == "1") {
                $metadata_arr[] = '<meta property="og:audio:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', wp_get_attachment_url($post->ID))) . '" />';
            }
            $metadata_arr[] = '<meta property="og:audio:type" content="' . esc_attr($mime_type) . '" />';
        }
        // Article: meta tags
        // Dates
        $metadata_arr[] = '<meta property="article:published_time" content="' . esc_attr(amt_iso8601_date($post->post_date)) . '" />';
        $metadata_arr[] = '<meta property="article:modified_time" content="' . esc_attr(amt_iso8601_date($post->post_modified)) . '" />';
        // Author
        // If a Facebook author profile URL has been provided, it has priority,
        // Otherwise fall back to the WordPress author archive.
        $fb_author_url = get_the_author_meta('amt_facebook_author_profile_url', $post->post_author);
        if (!empty($fb_author_url)) {
            $metadata_arr[] = '<meta property="article:author" content="' . esc_url_raw($fb_author_url, array('http', 'https', 'mailto')) . '" />';
        } else {
            //$metadata_arr[] = '<meta property="article:author" content="' . esc_url_raw( get_author_posts_url( get_the_author_meta( 'ID', $post->post_author ) ) ) . '" />';
            $metadata_arr[] = '<meta property="article:author" content="' . esc_url_raw(amt_get_local_author_profile_url(get_the_author_meta('ID', $post->post_author), $options)) . '" />';
        }
        // Publisher
        // If a Facebook publisher profile URL has been provided, it has priority.
        // Otherwise fall back to the WordPress blog home url.
        if (!empty($options['social_main_facebook_publisher_profile_url'])) {
            $metadata_arr[] = '<meta property="article:publisher" content="' . esc_url_raw($options['social_main_facebook_publisher_profile_url'], array('http', 'https', 'mailto')) . '" />';
        } else {
            $metadata_arr[] = '<meta property="article:publisher" content="' . esc_url_raw(trailingslashit(get_bloginfo('url'))) . '" />';
        }
        // Posts, pages, custom content types (attachments excluded, caught in previous clause)
        // Note: content might be multipage. Process with amt_process_paged() wherever needed.
    } elseif (is_singular()) {
        // Site Name
        $metadata_arr[] = '<meta property="og:site_name" content="' . esc_attr(get_bloginfo('name')) . '" />';
        // Type
        // og:type set to 'video.other' for posts with post format set to video
        if (get_post_format($post->ID) == 'video') {
            $og_type = 'video.other';
            // og:type set to 'product' if amt_is_product() validates
            // See:
            //  * https://developers.facebook.com/docs/reference/opengraph/object-type/product/
            //  * https://developers.facebook.com/docs/payments/product
        } elseif (amt_is_product()) {
            $og_type = 'product';
            // In any other case 'article' is used as the og:type
        } else {
            $og_type = 'article';
        }
        // Allow filtering of og:type
        $og_type = apply_filters('amt_opengraph_og_type_content', $og_type);
        // Set og:type meta tag.
        $metadata_arr[] = '<meta property="og:type" content="' . esc_attr($og_type) . '" />';
        // Title
        // Note: Contains multipage information
        $metadata_arr['og:title'] = '<meta property="og:title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
        // URL - Uses amt_get_permalink_for_multipage()
        $metadata_arr[] = '<meta property="og:url" content="' . esc_url_raw(amt_get_permalink_for_multipage($post)) . '" />';
        // Description - We use the description defined by Add-Meta-Tags
        // Note: Contains multipage information through amt_process_paged()
        $content_desc = amt_get_content_description($post);
        if (!empty($content_desc)) {
            $metadata_arr[] = '<meta property="og:description" content="' . esc_attr(amt_process_paged($content_desc)) . '" />';
        }
        // Locale
        $metadata_arr[] = '<meta property="og:locale" content="' . esc_attr(str_replace('-', '_', amt_get_language_content($options, $post))) . '" />';
        // og:updated_time
        $metadata_arr[] = '<meta property="og:updated_time" content="' . esc_attr(amt_iso8601_date($post->post_modified)) . '" />';
        // Image
        // First check if a global image override URL has been entered.
        // If yes, use this image URL and override all other images.
        $image_data = amt_get_image_attributes_array(amt_get_post_meta_image_url($post->ID));
        if (!empty($image_data)) {
            $image_size = apply_filters('amt_image_size_content', 'full');
            $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
            if (!empty($image_meta_tags)) {
                $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
            }
            //$global_image_override_url = amt_get_post_meta_image_url($post->ID);
            //if ( ! empty( $global_image_override_url ) ) {
            //    $metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $global_image_override_url ) . '" />';
            //    if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
            //        $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $global_image_override_url ) ) . '" />';
            //    }
            // Further image processing
        } else {
            // Media Limits
            $image_limit = amt_metadata_get_image_limit($options);
            $video_limit = amt_metadata_get_video_limit($options);
            $audio_limit = amt_metadata_get_audio_limit($options);
            // Counters
            $ic = 0;
            // image counter
            $vc = 0;
            // video counter
            $ac = 0;
            // audio counter
            // We store the featured image ID in this variable so that it can easily be excluded
            // when all images are parsed from the $attachments array.
            $featured_image_id = 0;
            // Set to true if any image attachments are found. Use to finally add the default image
            // if no image attachments have been found.
            $has_images = false;
            if (function_exists('has_post_thumbnail') && has_post_thumbnail($post->ID)) {
                // Allow filtering of the image size.
                $image_size = apply_filters('amt_image_size_content', 'full');
                $metadata_arr = array_merge($metadata_arr, amt_get_opengraph_image_metatags($options, get_post_thumbnail_id($post->ID), $size = $image_size));
                // Finally, set the $featured_image_id
                $featured_image_id = get_post_thumbnail_id($post->ID);
                // Images have been found.
                $has_images = true;
                // Increase image counter
                $ic++;
            }
            // Process all attachments and add metatags (featured image will be excluded)
            foreach ($attachments as $attachment) {
                // Excluded the featured image since
                if ($attachment->ID != $featured_image_id) {
                    $mime_type = get_post_mime_type($attachment->ID);
                    //$attachment_type = strstr( $mime_type, '/', true );
                    // See why we do not use strstr(): http://www.codetrax.org/issues/1091
                    $attachment_type = preg_replace('#\\/[^\\/]*$#', '', $mime_type);
                    if ('image' == $attachment_type && $ic < $image_limit) {
                        // Image tags
                        // Allow filtering of the image size.
                        $image_size = apply_filters('amt_image_size_content', 'full');
                        $metadata_arr = array_merge($metadata_arr, amt_get_opengraph_image_metatags($options, $attachment->ID, $size = $image_size));
                        // Images have been found.
                        $has_images = true;
                        // Increase image counter
                        $ic++;
                    } elseif ('video' == $attachment_type && $vc < $video_limit) {
                        if ($options["og_omit_video_metadata"] != "1") {
                            // Video tags
                            $metadata_arr[] = '<meta property="og:video" content="' . esc_url_raw(wp_get_attachment_url($attachment->ID)) . '" />';
                            if (is_ssl() || !is_ssl() && $options["has_https_access"] == "1") {
                                $metadata_arr[] = '<meta property="og:video:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', wp_get_attachment_url($attachment->ID))) . '" />';
                            }
                            //$metadata_arr[] = '<meta property="og:video:width" content="' . esc_attr( $main_size_meta[1] ) . '" />';
                            //$metadata_arr[] = '<meta property="og:video:height" content="' . esc_attr( $main_size_meta[2] ) . '" />';
                            $metadata_arr[] = '<meta property="og:video:type" content="' . esc_attr($mime_type) . '" />';
                            // Increase video counter
                            $vc++;
                        }
                    } elseif ('audio' == $attachment_type && $ac < $audio_limit) {
                        // Audio tags
                        $metadata_arr[] = '<meta property="og:audio" content="' . esc_url_raw(wp_get_attachment_url($attachment->ID)) . '" />';
                        if (is_ssl() || !is_ssl() && $options["has_https_access"] == "1") {
                            $metadata_arr[] = '<meta property="og:audio:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', wp_get_attachment_url($attachment->ID))) . '" />';
                        }
                        $metadata_arr[] = '<meta property="og:audio:type" content="' . esc_attr($mime_type) . '" />';
                        // Increase audio counter
                        $ac++;
                    }
                }
            }
            // Embedded Media
            foreach ($embedded_media['images'] as $embedded_item) {
                if ($ic == $image_limit) {
                    break;
                }
                $metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw($embedded_item['image']) . '" />';
                $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', $embedded_item['image'])) . '" />';
                if (apply_filters('amt_extended_image_tags', true)) {
                    $metadata_arr[] = '<meta property="og:image:width" content="' . esc_attr($embedded_item['width']) . '" />';
                    $metadata_arr[] = '<meta property="og:image:height" content="' . esc_attr($embedded_item['height']) . '" />';
                    $metadata_arr[] = '<meta property="og:image:type" content="image/jpeg" />';
                }
                // Images have been found.
                $has_images = true;
                // Increase image counter
                $ic++;
            }
            foreach ($embedded_media['videos'] as $embedded_item) {
                if ($options["og_omit_video_metadata"] != "1") {
                    if ($vc == $video_limit) {
                        break;
                    }
                    $metadata_arr[] = '<meta property="og:video" content="' . esc_url_raw($embedded_item['player']) . '" />';
                    $metadata_arr[] = '<meta property="og:video:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', $embedded_item['player'])) . '" />';
                    $metadata_arr[] = '<meta property="og:video:type" content="application/x-shockwave-flash" />';
                    $metadata_arr[] = '<meta property="og:video:width" content="' . esc_attr($embedded_item['width']) . '" />';
                    $metadata_arr[] = '<meta property="og:video:height" content="' . esc_attr($embedded_item['height']) . '" />';
                    // Increase video counter
                    $vc++;
                }
            }
            foreach ($embedded_media['sounds'] as $embedded_item) {
                if ($ac == $audio_limit) {
                    break;
                }
                $metadata_arr[] = '<meta property="og:audio" content="' . esc_url_raw($embedded_item['player']) . '" />';
                $metadata_arr[] = '<meta property="og:audio:secure_url" content="' . esc_url_raw(str_replace('http:', 'https:', $embedded_item['player'])) . '" />';
                $metadata_arr[] = '<meta property="og:audio:type" content="application/x-shockwave-flash" />';
                // Increase audio counter
                $ac++;
            }
            // If no images have been found so far use the default image, if set.
            if ($has_images === false) {
                // Use the default image, if one has been set.
                $image_data = amt_get_default_image_data();
                if (!empty($image_data)) {
                    $image_size = apply_filters('amt_image_size_content', 'full');
                    $image_meta_tags = amt_get_opengraph_image_metatags($options, $image_data, $size = $image_size);
                    if (!empty($image_meta_tags)) {
                        $metadata_arr = array_merge($metadata_arr, $image_meta_tags);
                    }
                }
                //$metadata_arr[] = '<meta property="og:image" content="' . esc_url_raw( $options["default_image_url"] ) . '" />';
                //if ( is_ssl() || ( ! is_ssl() && $options["has_https_access"] == "1" ) ) {
                //    $metadata_arr[] = '<meta property="og:image:secure_url" content="' . esc_url_raw( str_replace('http:', 'https:', $options["default_image_url"] ) ) . '" />';
                //}
            }
        }
        // og:referenced
        $referenced_url_list = amt_get_referenced_items($post);
        foreach ($referenced_url_list as $referenced_url) {
            $referenced_url = trim($referenced_url);
            if (!empty($referenced_url)) {
                $metadata_arr[] = '<meta property="og:referenced" content="' . esc_url_raw($referenced_url) . '" />';
            }
        }
        // Article: meta tags
        if ($og_type == 'article') {
            // Dates
            $metadata_arr[] = '<meta property="article:published_time" content="' . esc_attr(amt_iso8601_date($post->post_date)) . '" />';
            $metadata_arr[] = '<meta property="article:modified_time" content="' . esc_attr(amt_iso8601_date($post->post_modified)) . '" />';
            // Author
            // If a Facebook author profile URL has been provided, it has priority,
            // Otherwise fall back to the WordPress author archive.
            $fb_author_url = get_the_author_meta('amt_facebook_author_profile_url', $post->post_author);
            if (!empty($fb_author_url)) {
                $metadata_arr[] = '<meta property="article:author" content="' . esc_url_raw($fb_author_url, array('http', 'https', 'mailto')) . '" />';
            } else {
                //$metadata_arr[] = '<meta property="article:author" content="' . esc_url_raw( get_author_posts_url( get_the_author_meta( 'ID', $post->post_author ) ) ) . '" />';
                $metadata_arr[] = '<meta property="article:author" content="' . esc_url_raw(amt_get_local_author_profile_url(get_the_author_meta('ID', $post->post_author), $options)) . '" />';
            }
            // Publisher
            // If a Facebook publisher profile URL has been provided, it has priority.
            // Otherwise fall back to the WordPress blog home url.
            if (!empty($options['social_main_facebook_publisher_profile_url'])) {
                $metadata_arr[] = '<meta property="article:publisher" content="' . esc_url_raw($options['social_main_facebook_publisher_profile_url'], array('http', 'https', 'mailto')) . '" />';
            } else {
                $metadata_arr[] = '<meta property="article:publisher" content="' . esc_url_raw(trailingslashit(get_bloginfo('url'))) . '" />';
            }
            /*
            // article:section: We use the first category as the section.
            $first_cat = amt_get_first_category($post);
            if ( ! empty( $first_cat ) ) {
                $metadata_arr[] = '<meta property="article:section" content="' . esc_attr( $first_cat ) . '" />';
            }
            */
            // article:section: We use print an ``article:section`` meta tag for each of the post's categories.
            $categories = get_the_category($post->ID);
            $categories = apply_filters('amt_post_categories_for_opengraph', $categories);
            foreach ($categories as $cat) {
                $section = trim($cat->cat_name);
                if (!empty($section) && $cat->slug != 'uncategorized') {
                    $metadata_arr[] = '<meta property="article:section" content="' . esc_attr($section) . '" />';
                }
            }
            // article:tag: Keywords are listed as post tags
            $keywords = explode(',', amt_get_content_keywords($post, $auto = true, $exclude_categories = true));
            foreach ($keywords as $tag) {
                $tag = trim($tag);
                if (!empty($tag)) {
                    $metadata_arr[] = '<meta property="article:tag" content="' . esc_attr($tag) . '" />';
                }
            }
        } elseif ($og_type == 'video.other') {
            // Dates
            $metadata_arr[] = '<meta property="video:release_date" content="' . esc_attr(amt_iso8601_date($post->post_date)) . '" />';
            // video:tag: Keywords are listed as post tags
            $keywords = explode(',', amt_get_content_keywords($post));
            foreach ($keywords as $tag) {
                $tag = trim($tag);
                if (!empty($tag)) {
                    $metadata_arr[] = '<meta property="video:tag" content="' . esc_attr($tag) . '" />';
                }
            }
        } elseif ($og_type == 'product') {
            // Extend the current metadata with properties of the Product object.
            // See:
            //  * https://developers.facebook.com/docs/reference/opengraph/object-type/product/
            //  * https://developers.facebook.com/docs/payments/product
            $metadata_arr = apply_filters('amt_product_data_opengraph', $metadata_arr, $post);
        }
    }
    // Filtering of the generated Opengraph metadata
    $metadata_arr = apply_filters('amt_opengraph_metadata_head', $metadata_arr);
    return $metadata_arr;
}
Esempio n. 2
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function amt_add_dublin_core_metadata_head($post, $attachments, $embedded_media, $options)
{
    if (apply_filters('amt_exclude_dublin_core_metadata', false)) {
        return array();
    }
    $metadata_arr = array();
    $do_auto_dublincore = $options["auto_dublincore"] == "1" ? true : false;
    if (!$do_auto_dublincore) {
        return $metadata_arr;
    }
    // Custom content override
    if (amt_is_custom($post, $options)) {
        // Return metadata with:
        // add_filter( 'amt_custom_metadata_dublin_core', 'my_function', 10, 5 );
        // Return an array of meta tags. Array item format: ['key_can_be_whatever'] = '<meta name="foo" content="bar" />'
        $metadata_arr = apply_filters('amt_custom_metadata_dublin_core', $metadata_arr, $post, $options, $attachments, $embedded_media);
        return $metadata_arr;
    }
    if (!is_singular() || is_front_page()) {
        // is_front_page() is used for the case in which a static page is used as the front page.
        // Dublin Core metadata has a meaning for content only.
        return array();
    }
    // The Dublin Core metadata generator does not support products or product groups.
    if (amt_is_product() || amt_is_product_group()) {
        return array();
    }
    // Title
    // Note: Contains multipage information through amt_process_paged()
    $metadata_arr['dcterms.title'] = '<meta name="dcterms.title" content="' . esc_attr(amt_get_title_for_metadata($options, $post)) . '" />';
    // Resource identifier - Uses amt_get_permalink_for_multipage()
    $metadata_arr[] = '<meta name="dcterms.identifier" content="' . esc_url_raw(amt_get_permalink_for_multipage($post)) . '" />';
    $metadata_arr[] = '<meta name="dcterms.creator" content="' . esc_attr(amt_get_dublin_core_author_notation($post)) . '" />';
    //$metadata_arr[] = '<meta name="dcterms.date" content="' . esc_attr( amt_iso8601_date($post->post_date) ) . '" />';
    $metadata_arr[] = '<meta name="dcterms.created" content="' . esc_attr(amt_iso8601_date($post->post_date)) . '" />';
    $metadata_arr[] = '<meta name="dcterms.available" content="' . esc_attr(amt_iso8601_date($post->post_date)) . '" />';
    //$metadata_arr[] = '<meta name="dcterms.issued" content="' . esc_attr( amt_iso8601_date($post->post_date) ) . '" />';
    $metadata_arr[] = '<meta name="dcterms.modified" content="' . esc_attr(amt_iso8601_date($post->post_modified)) . '" />';
    // Description
    // We use the same description as the ``description`` meta tag.
    // Note: Contains multipage information through amt_process_paged()
    $content_desc = amt_get_content_description($post);
    if (!empty($content_desc)) {
        $metadata_arr[] = '<meta name="dcterms.description" content="' . esc_attr(amt_process_paged($content_desc)) . '" />';
    }
    // Keywords
    if (!is_attachment()) {
        // Attachments do not support keywords
        // dcterms.subject - one for each keyword.
        $keywords = explode(',', amt_get_content_keywords($post));
        foreach ($keywords as $subject) {
            $subject = trim($subject);
            if (!empty($subject)) {
                $metadata_arr[] = '<meta name="dcterms.subject" content="' . esc_attr($subject) . '" />';
            }
        }
    }
    $metadata_arr[] = '<meta name="dcterms.language" content="' . esc_attr(amt_get_language_content($options, $post)) . '" />';
    $metadata_arr[] = '<meta name="dcterms.publisher" content="' . esc_url_raw(trailingslashit(get_bloginfo('url'))) . '" />';
    // Copyright page
    $copyright_url = amt_get_site_copyright_url($options);
    if (empty($copyright_url)) {
        $copyright_url = trailingslashit(get_bloginfo('url'));
    }
    if (!empty($copyright_url)) {
        $metadata_arr[] = '<meta name="dcterms.rights" content="' . esc_url_raw($copyright_url) . '" />';
    }
    // License
    $license_url = '';
    // The following requires creative commons configurator
    if (function_exists('bccl_get_license_url')) {
        $license_url = bccl_get_license_url();
    }
    // Allow filtering of the license URL
    $license_url = apply_filters('amt_dublin_core_license', $license_url, $post->ID);
    // Add metatag if $license_url is not empty.
    if (!empty($license_url)) {
        $metadata_arr[] = '<meta name="dcterms.license" content="' . esc_url_raw($license_url) . '" />';
    }
    // Coverage
    $metadata_arr[] = '<meta name="dcterms.coverage" content="World" />';
    if (is_attachment()) {
        $mime_type = get_post_mime_type($post->ID);
        //$attachment_type = strstr( $mime_type, '/', true );
        // See why we do not use strstr(): http://www.codetrax.org/issues/1091
        $attachment_type = preg_replace('#\\/[^\\/]*$#', '', $mime_type);
        $metadata_arr[] = '<meta name="dcterms.isPartOf" content="' . esc_url_raw(get_permalink($post->post_parent)) . '" />';
        if ('image' == $attachment_type) {
            $metadata_arr[] = '<meta name="dcterms.type" content="Image" />';
            $metadata_arr[] = '<meta name="dcterms.format" content="' . $mime_type . '" />';
        } elseif ('video' == $attachment_type) {
            $metadata_arr[] = '<meta name="dcterms.type" content="MovingImage" />';
            $metadata_arr[] = '<meta name="dcterms.format" content="' . $mime_type . '" />';
        } elseif ('audio' == $attachment_type) {
            $metadata_arr[] = '<meta name="dcterms.type" content="Sound" />';
            $metadata_arr[] = '<meta name="dcterms.format" content="' . $mime_type . '" />';
        }
        // Finally add the hasFormat
        $metadata_arr[] = '<meta name="dcterms.hasFormat" content="' . esc_url_raw(wp_get_attachment_url($post->ID)) . '" />';
    } else {
        // Default: Text
        $metadata_arr[] = '<meta name="dcterms.type" content="Text" />';
        $metadata_arr[] = '<meta name="dcterms.format" content="text/html" />';
        // Add media files
        // Media Limits
        $image_limit = amt_metadata_get_image_limit($options);
        $video_limit = amt_metadata_get_video_limit($options);
        $audio_limit = amt_metadata_get_audio_limit($options);
        // Counters
        $ic = 0;
        // image counter
        $vc = 0;
        // video counter
        $ac = 0;
        // audio counter
        // List attachments
        foreach ($attachments as $attachment) {
            $mime_type = get_post_mime_type($attachment->ID);
            //$attachment_type = strstr( $mime_type, '/', true );
            // See why we do not use strstr(): http://www.codetrax.org/issues/1091
            $attachment_type = preg_replace('#\\/[^\\/]*$#', '', $mime_type);
            if ('image' == $attachment_type && $ic < $image_limit) {
                $metadata_arr[] = '<meta name="dcterms.hasPart" content="' . esc_url_raw(get_permalink($attachment->ID)) . '" />';
                // Increase image counter
                $ic++;
            } elseif ('video' == $attachment_type && $vc < $video_limit) {
                $metadata_arr[] = '<meta name="dcterms.hasPart" content="' . esc_url_raw(get_permalink($attachment->ID)) . '" />';
                // Increase video counter
                $vc++;
            } elseif ('audio' == $attachment_type && $ac < $audio_limit) {
                $metadata_arr[] = '<meta name="dcterms.hasPart" content="' . esc_url_raw(get_permalink($attachment->ID)) . '" />';
                // Increase audio counter
                $ac++;
            }
        }
        // Embedded Media
        foreach ($embedded_media['images'] as $embedded_item) {
            if ($ic == $image_limit) {
                break;
            }
            $metadata_arr[] = '<meta name="dcterms.hasPart" content="' . esc_url_raw($embedded_item['page']) . '" />';
            // Increase image counter
            $ic++;
        }
        foreach ($embedded_media['videos'] as $embedded_item) {
            if ($vc == $video_limit) {
                break;
            }
            $metadata_arr[] = '<meta name="dcterms.hasPart" content="' . esc_url_raw($embedded_item['page']) . '" />';
            // Increase video counter
            $vc++;
        }
        foreach ($embedded_media['sounds'] as $embedded_item) {
            if ($ac == $audio_limit) {
                break;
            }
            $metadata_arr[] = '<meta name="dcterms.hasPart" content="' . esc_url_raw($embedded_item['page']) . '" />';
            // Increase audio counter
            $ac++;
        }
    }
    /**
     * WordPress Post Formats: http://codex.wordpress.org/Post_Formats
     * Dublin Core Format: http://dublincore.org/documents/dcmi-terms/#terms-format
     * Dublin Core DCMIType: http://dublincore.org/documents/dcmi-type-vocabulary/
     */
    /**
     * TREAT ALL POST FORMATS AS TEXT (for now)
     */
    /**
    $format = get_post_format( $post->id );
    if ( empty($format) || $format=="aside" || $format=="link" || $format=="quote" || $format=="status" || $format=="chat") {
        // Default format
        $metadata_arr[] = '<meta name="dcterms.type" content="Text" />';
        $metadata_arr[] = '<meta name="dcterms.format" content="text/html" />';
    } elseif ($format=="gallery") {
        $metadata_arr[] = '<meta name="dcterms.type" content="Collection" />';
        // $metadata_arr[] = '<meta name="dcterms.format" content="image" />';
    } elseif ($format=="image") {
        $metadata_arr[] = '<meta name="dcterms.type" content="Image" />';
        // $metadata_arr[] = '<meta name="dcterms.format" content="image/png" />';
    } elseif ($format=="video") {
        $metadata_arr[] = '<meta name="dcterms.type" content="Moving Image" />';
        $metadata_arr[] = '<meta name="dcterms.format" content="application/x-shockwave-flash" />';
    } elseif ($format=="audio") {
        $metadata_arr[] = '<meta name="dcterms.type" content="Sound" />';
        $metadata_arr[] = '<meta name="dcterms.format" content="audio/mpeg" />';
    }
    */
    // Filtering of the generated Dublin Core metadata
    $metadata_arr = apply_filters('amt_dublin_core_metadata_head', $metadata_arr);
    return $metadata_arr;
}