The Headers. Based upon a post from Julio Biason. * Version: 2.3.5 * Author: Andy Fragen * Author URI: https://thefragens.com * License: GNU General Public License v2 * License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html * Text Domain: add-custom-header-images * Domain Path: /languages * GitHub Plugin URI: https://github.com/afragen/add-custom-header-images * Requires at least: 5.2 * Requires PHP: 5.6 */ /** * Class Add_Custom_Header_Images */ class Add_Custom_Header_Images { /** * Variable to hold the data for `get_page_by_title()`. * * @var array|null|\WP_Post */ private $the_headers_page; /** * Variable to hold header image URL. * * @var string */ public $header_image; /** * Variable to hold header images. * * @var array */ public $header_images; /** * Variable to hold image attributes. * * @var array */ private $image_attr; /** * Constructor. */ public function __construct() { $the_headers_title = __( 'The Headers', 'add-custom-header-images' ); $query = new WP_Query( [ 'post_type' => 'page', 'title' => $the_headers_title, 'post_status' => 'all', ] ); $this->the_headers_page = $query->post; $this->run(); } /** * Let's get started. * * @return bool */ public function run() { if ( ( is_admin() && null === $this->the_headers_page ) ) { add_action( 'admin_notices', [ $this, 'headers_page_not_present' ] ); return false; } add_action( 'after_setup_theme', [ $this, 'new_default_header_images' ], 99 ); add_action( 'after_setup_theme', [ $this, 'setup_default_header_image' ], 100 ); add_filter( 'wp_get_attachment_image_attributes', [ $this, 'get_image_attributes' ], 100, 3 ); } /** * Disable plugin if 'The Headers' page does not exist. */ public function headers_page_not_present() { echo '

'; echo wp_kses_post( __( 'Add Custom Header Images requires a page titled The Headers.', 'add-custom-header-images' ) ); echo '

'; } /** * Remove default header images. */ public function remove_default_header_images() { global $_wp_default_headers; if ( empty( $_wp_default_headers ) ) { return false; } $header_ids = []; foreach ( (array) array_keys( $_wp_default_headers ) as $key ) { if ( ! is_int( $key ) ) { $header_ids[] = $key; } } unregister_default_headers( $header_ids ); } /** * Add new default header images. */ public function new_default_header_images() { if ( ! $this->the_headers_page instanceof \WP_Post ) { return false; } $this->remove_default_header_images(); $header_images = $this->get_images_from_post( $this->the_headers_page ); register_default_headers( $header_images ); } /** * Get images from attachments and blocks. * * @param \WP_Post $post Post object. * @return array $header_images */ private function get_images_from_post( \WP_Post $post ) { $images_query = new \WP_Query( [ 'post_parent' => $post->ID, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => 'ASC', 'orderby' => 'menu_order ID', ] ); // Get images from blocks. $parsed_blocks = \parse_blocks( $post->post_content ); $parsed_images = array_filter( $parsed_blocks, function ( $block ) { return 'core/image' === $block['blockName']; } ); $blocks = []; foreach ( $parsed_images as $block ) { $id = $block['attrs']['id']; $blocks[] = (object) [ 'ID' => $id, 'post_title' => get_the_title( $id ), ]; } $images = array_merge( $images_query->posts, $blocks ); // Make default header image arrays. $header_images = []; $image_ids = []; foreach ( $images as $image ) { wp_get_attachment_image( $image->ID, 'medium' ); $header_images[] = [ 'url' => wp_get_attachment_url( $image->ID ), 'thumbnail_url' => $this->image_attr['src'], 'description' => $image->post_title, 'attachment_id' => $image->ID, 'alt_text' => $this->image_attr['alt'], ]; $image_ids[] = $image->ID; } $header_images = $this->filter_headers( $header_images, $image_ids ); $this->header_images = $header_images; return $header_images; } /** * Remove duplicate $headers. * * @param array $images Array of image data. * @param array $image_ids Array of image IDs. * @return array $images */ private function filter_headers( $images, $image_ids ) { $image_ids = array_flip( array_unique( $image_ids ) ); $images = array_filter( $images, function ( $id ) use ( &$image_ids ) { if ( array_key_exists( $id['attachment_id'], $image_ids ) ) { unset( $image_ids[ $id['attachment_id'] ] ); return $id; } } ); return (array) $images; } /** * Add default header image if theme doesn't support it. * * @return void */ public function setup_default_header_image() { if ( ! current_theme_supports( 'custom-header' ) ) { add_theme_support( 'custom-header' ); $this->header_image = get_header_image(); if ( ! function_exists( 'wp_body_open' ) ) { /** * Shim for wp_body_open, ensuring backward compatibility with versions of WordPress older than 5.2. */ function wp_body_open() { do_action( 'wp_body_open' ); } } $alt_text = array_map( function( $img_arr ) { if ( $this->header_image === $img_arr['url'] ) { return $img_arr['alt_text']; } }, (array) $this->header_images ); $alt_text = array_filter( $alt_text ); $alt_text = array_pop( $alt_text ); add_action( 'wp_body_open', function () use ( $alt_text ) { printf( /* translators: 1: image URL, 2: alt text */ '

', esc_attr( $this->header_image ), esc_attr( $alt_text ) ); } ); add_action( 'wp_head', [ $this, 'header_image_style' ] ); } } /** * Get image attributes. * * @param string[] $attr Array of attribute values for the image markup, keyed by attribute name. * @param WP_Post $attachment Image attachment post. * @param string|int[] $size Requested image size. Can be any registered image size name, or * an array of width and height values in pixels (in that order). * * @return array */ public function get_image_attributes( $attr, $attachment, $size ) { $this->image_attr = $attr; return $attr; } /** * Header image CSS styling. * * @return void */ public function header_image_style() { ?>