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<?php/**
 * Server-side rendering of the `core/footnotes` block.
 *
 * @package WordPress
 */
 
 /**
 * Renders the `core/footnotes` block on the server.
 *
 * @since 6.3.0
 *
 * @param array    $attributes Block attributes.
 * @param string   $content    Block default content.
 * @param WP_Block $block      Block instance.
 *
 * @return string Returns the HTML representing the footnotes.
 */
 function render_block_core_footnotes( $attributes, $content, $block ) {
 // Bail out early if the post ID is not set for some reason.
 if ( empty( $block->context['postId'] ) ) {
 return '';
 }
 
 if ( post_password_required( $block->context['postId'] ) ) {
 return;
 }
 
 $footnotes = get_post_meta( $block->context['postId'], 'footnotes', true );
 
 if ( ! $footnotes ) {
 return;
 }
 
 $footnotes = json_decode( $footnotes, true );
 
 if ( ! is_array( $footnotes ) || count( $footnotes ) === 0 ) {
 return '';
 }
 
 $wrapper_attributes = get_block_wrapper_attributes();
 $footnote_index     = 1;
 
 $block_content = '';
 
 foreach ( $footnotes as $footnote ) {
 // Translators: %d: Integer representing the number of return links on the page.
 $aria_label     = sprintf( __( 'Jump to footnote reference %1$d' ), $footnote_index );
 $block_content .= sprintf(
 '<li id="%1$s">%2$s <a href="#%1$s-link" aria-label="%3$s">??</a></li>',
 $footnote['id'],
 $footnote['content'],
 $aria_label
 );
 ++$footnote_index;
 }
 
 return sprintf(
 '<ol %1$s>%2$s</ol>',
 $wrapper_attributes,
 $block_content
 );
 }
 
 /**
 * Registers the `core/footnotes` block on the server.
 *
 * @since 6.3.0
 */
 function register_block_core_footnotes() {
 register_block_type_from_metadata(
 __DIR__ . '/footnotes',
 array(
 'render_callback' => 'render_block_core_footnotes',
 )
 );
 }
 add_action( 'init', 'register_block_core_footnotes' );
 
 
 /**
 * Registers the footnotes meta field required for footnotes to work.
 *
 * @since 6.5.0
 */
 function register_block_core_footnotes_post_meta() {
 $post_types = get_post_types( array( 'show_in_rest' => true ) );
 foreach ( $post_types as $post_type ) {
 // Only register the meta field if the post type supports the editor, custom fields, and revisions.
 if (
 post_type_supports( $post_type, 'editor' ) &&
 post_type_supports( $post_type, 'custom-fields' ) &&
 post_type_supports( $post_type, 'revisions' )
 ) {
 register_post_meta(
 $post_type,
 'footnotes',
 array(
 'show_in_rest'      => true,
 'single'            => true,
 'type'              => 'string',
 'revisions_enabled' => true,
 )
 );
 }
 }
 }
 /*
 * Most post types are registered at priority 10, so use priority 20 here in
 * order to catch them.
 */
 add_action( 'init', 'register_block_core_footnotes_post_meta', 20 );
 
 /**
 * Adds the footnotes field to the revisions display.
 *
 * @since 6.3.0
 *
 * @param array $fields The revision fields.
 * @return array The revision fields.
 */
 function wp_add_footnotes_to_revision( $fields ) {
 $fields['footnotes'] = __( 'Footnotes' );
 return $fields;
 }
 add_filter( '_wp_post_revision_fields', 'wp_add_footnotes_to_revision' );
 
 /**
 * Gets the footnotes field from the revision for the revisions screen.
 *
 * @since 6.3.0
 *
 * @param string $revision_field The field value, but $revision->$field
 *                               (footnotes) does not exist.
 * @param string $field          The field name, in this case "footnotes".
 * @param object $revision       The revision object to compare against.
 * @return string The field value.
 */
 function wp_get_footnotes_from_revision( $revision_field, $field, $revision ) {
 return get_metadata( 'post', $revision->ID, $field, true );
 }
 add_filter( '_wp_post_revision_field_footnotes', 'wp_get_footnotes_from_revision', 10, 3 );
 
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