$is_custom_body_class_enabled ) { if ( ( get_post_type() == $post_type_slug ) && $is_custom_body_class_enabled ) { // Skip adding meta box for post types where Gutenberg is enabled // if ( // function_exists( 'use_block_editor_for_post_type' ) // && use_block_editor_for_post_type( $post_type_slug ) // ) { // continue; // go to the beginning of next iteration // } add_meta_box( 'asenha-custom-body-class', // ID of meta box 'Custom <body> Class', // Title of meta box [ $this, 'output_custom_body_class_meta_box' ], // Callback function $post_type_slug, // The screen on which the meta box should be output to 'normal', // context 'high' // priority // array(), // $args to pass to callback function. Ref: https://developer.wordpress.org/reference/functions/add_meta_box/#comment-342 ); } } } /** * Render External Permalink meta box * * @since 3.9.0 */ public function output_custom_body_class_meta_box( $post ) { ?>

Use blank space to separate multiple classes, e.g. first-class second-class

ID, 'custom_body_class_nonce', false, true ); ?>

tag * * @since 4.4.0 */ public function append_custom_body_class( $classes ) { // Only add custom body classes to the singular view of enabled post types if ( is_singular() ) { global $post; $custom_body_classes = get_post_meta( $post->ID, '_custom_body_class', true ); if ( ! empty( $custom_body_classes ) ) { $custom_body_classes = explode( ' ', $custom_body_classes ); foreach( $custom_body_classes as $custom_body_class ) { $classes[] = sanitize_html_class( $custom_body_class ); } } } return $classes; } }