1<?php
  2/**
  3 * Post Meta source for the block bindings.
  4 *
  5 * @since 6.5.0
  6 * @package WordPress
  7 * @subpackage Block Bindings
  8 */
  9
 10/**
 11 * Gets value for Post Meta source.
 12 *
 13 * @since 6.5.0
 14 * @access private
 15 *
 16 * @param array    $source_args    Array containing source arguments used to look up the override value.
 17 *                                 Example: array( "key" => "foo" ).
 18 * @param WP_Block $block_instance The block instance.
 19 * @return mixed The value computed for the source.
 20 */
 21function _block_bindings_post_meta_get_value( array $source_args, $block_instance ) {
 22	if ( empty( $source_args['key'] ) ) {
 23		return null;
 24	}
 25
 26	if ( empty( $block_instance->context['postId'] ) ) {
 27		return null;
 28	}
 29	$post_id = $block_instance->context['postId'];
 30
 31	// If a post isn't public, we need to prevent unauthorized users from accessing the post meta.
 32	$post = get_post( $post_id );
 33	if ( ( ! is_post_publicly_viewable( $post ) && ! current_user_can( 'read_post', $post_id ) ) || post_password_required( $post ) ) {
 34		return null;
 35	}
 36
 37	// Check if the meta field is protected.
 38	if ( is_protected_meta( $source_args['key'], 'post' ) ) {
 39		return null;
 40	}
 41
 42	// Check if the meta field is registered to be shown in REST.
 43	$meta_keys = get_registered_meta_keys( 'post', $block_instance->context['postType'] );
 44	// Add fields registered for all subtypes.
 45	$meta_keys = array_merge( $meta_keys, get_registered_meta_keys( 'post', '' ) );
 46	if ( empty( $meta_keys[ $source_args['key'] ]['show_in_rest'] ) ) {
 47		return null;
 48	}
 49
 50	return get_post_meta( $post_id, $source_args['key'], true );
 51}
 52
 53/**
 54 * Registers Post Meta source in the block bindings registry.
 55 *
 56 * @since 6.5.0
 57 * @access private
 58 */
 59function _register_block_bindings_post_meta_source() {
 60	register_block_bindings_source(
 61		'core/post-meta',
 62		array(
 63			'label'              => _x( 'Post Meta', 'block bindings source' ),
 64			'get_value_callback' => '_block_bindings_post_meta_get_value',
 65			'uses_context'       => array( 'postId', 'postType' ),
 66		)
 67	);
 68}
 69
 70add_action( 'init', '_register_block_bindings_post_meta_source' );
 71