<?php 
/** 
 * Server-side rendering of the `core/comments` block. 
 * 
 * @package WordPress 
 */ 
 
/** 
 * Renders the `core/comments` block on the server. 
 * 
 * This render callback is mainly for rendering a dynamic, legacy version of 
 * this block (the old `core/post-comments`). It uses the `comments_template()` 
 * function to generate the output, in the same way as classic PHP themes. 
 * 
 * As this callback will always run during SSR, first we need to check whether 
 * the block is in legacy mode. If not, the HTML generated in the editor is 
 * returned instead. 
 * 
 * @since 6.1.0 
 * 
 * @global WP_Post $post Global post object. 
 * 
 * @param array    $attributes Block attributes. 
 * @param string   $content    Block default content. 
 * @param WP_Block $block      Block instance. 
 * @return string Returns the filtered post comments for the current post wrapped inside "p" tags. 
 */ 
function render_block_core_comments( $attributes, $content, $block ) { 
    global $post; 
 
    $post_id = $block->context['postId']; 
    if ( ! isset( $post_id ) ) { 
        return ''; 
    } 
 
    // Return early if there are no comments and comments are closed. 
    if ( ! comments_open( $post_id ) && (int) get_comments_number( $post_id ) === 0 ) { 
        return ''; 
    } 
 
    // If this isn't the legacy block, we need to render the static version of this block. 
    $is_legacy = 'core/post-comments' === $block->name || ! empty( $attributes['legacy'] ); 
    if ( ! $is_legacy ) { 
        return $block->render( array( 'dynamic' => false ) ); 
    } 
 
    $post_before = $post; 
    $post        = get_post( $post_id ); 
    setup_postdata( $post ); 
 
    ob_start(); 
 
    /* 
     * There's a deprecation warning generated by WP Core. 
     * Ideally this deprecation is removed from Core. 
     * In the meantime, this removes it from the output. 
     */ 
    add_filter( 'deprecated_file_trigger_error', '__return_false' ); 
    comments_template(); 
    remove_filter( 'deprecated_file_trigger_error', '__return_false' ); 
 
    $output = ob_get_clean(); 
    $post   = $post_before; 
 
    $classnames = array(); 
    // Adds the old class name for styles' backwards compatibility. 
    if ( isset( $attributes['legacy'] ) ) { 
        $classnames[] = 'wp-block-post-comments'; 
    } 
    if ( isset( $attributes['textAlign'] ) ) { 
        $classnames[] = 'has-text-align-' . $attributes['textAlign']; 
    } 
 
    $wrapper_attributes = get_block_wrapper_attributes( 
        array( 'class' => implode( ' ', $classnames ) ) 
    ); 
 
    /* 
     * Enqueues scripts and styles required only for the legacy version. That is 
     * why they are not defined in `block.json`. 
     */ 
    wp_enqueue_script( 'comment-reply' ); 
    enqueue_legacy_post_comments_block_styles( $block->name ); 
 
    return sprintf( '<div %1$s>%2$s</div>', $wrapper_attributes, $output ); 
} 
 
/** 
 * Registers the `core/comments` block on the server. 
 * 
 * @since 6.1.0 
 */ 
function register_block_core_comments() { 
    register_block_type_from_metadata( 
        __DIR__ . '/comments', 
        array( 
            'render_callback'   => 'render_block_core_comments', 
            'skip_inner_blocks' => true, 
        ) 
    ); 
} 
add_action( 'init', 'register_block_core_comments' ); 
 
/** 
 * Use the button block classes for the form-submit button. 
 * 
 * @since 6.1.0 
 * 
 * @param array $fields The default comment form arguments. 
 * 
 * @return array Returns the modified fields. 
 */ 
function comments_block_form_defaults( $fields ) { 
    if ( wp_is_block_theme() ) { 
        $fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s wp-block-button__link ' . wp_theme_get_element_class_name( 'button' ) . '" value="%4$s" />'; 
        $fields['submit_field']  = '<p class="form-submit wp-block-button">%1$s %2$s</p>'; 
    } 
 
    return $fields; 
} 
add_filter( 'comment_form_defaults', 'comments_block_form_defaults' ); 
 
/** 
 * Enqueues styles from the legacy `core/post-comments` block. These styles are 
 * required only by the block's fallback. 
 * 
 * @since 6.1.0 
 * 
 * @param string $block_name Name of the new block type. 
 */ 
function enqueue_legacy_post_comments_block_styles( $block_name ) { 
    static $are_styles_enqueued = false; 
 
    if ( ! $are_styles_enqueued ) { 
        $handles = array( 
            'wp-block-post-comments', 
            'wp-block-buttons', 
            'wp-block-button', 
        ); 
        foreach ( $handles as $handle ) { 
            wp_enqueue_block_style( $block_name, array( 'handle' => $handle ) ); 
        } 
        $are_styles_enqueued = true; 
    } 
} 
 
/** 
 * Ensures backwards compatibility for any users running the Gutenberg plugin 
 * who have used Post Comments before it was merged into Comments Query Loop. 
 * 
 * The same approach was followed when core/query-loop was renamed to 
 * core/post-template. 
 * 
 * @since 6.1.0 
 * 
 * @see https://github.com/WordPress/gutenberg/pull/41807 
 * @see https://github.com/WordPress/gutenberg/pull/32514 
 */ 
function register_legacy_post_comments_block() { 
    $registry = WP_Block_Type_Registry::get_instance(); 
 
    /* 
     * Remove the old `post-comments` block if it was already registered, as it 
     * is about to be replaced by the type defined below. 
     */ 
    if ( $registry->is_registered( 'core/post-comments' ) ) { 
        unregister_block_type( 'core/post-comments' ); 
    } 
 
    // Recreate the legacy block metadata. 
    $metadata = array( 
        'name'              => 'core/post-comments', 
        'category'          => 'theme', 
        'attributes'        => array( 
            'textAlign' => array( 
                'type' => 'string', 
            ), 
        ), 
        'uses_context'      => array( 
            'postId', 
            'postType', 
        ), 
        'supports'          => array( 
            'html'       => false, 
            'align'      => array( 'wide', 'full' ), 
            'typography' => array( 
                'fontSize'                      => true, 
                'lineHeight'                    => true, 
                '__experimentalFontStyle'       => true, 
                '__experimentalFontWeight'      => true, 
                '__experimentalLetterSpacing'   => true, 
                '__experimentalTextTransform'   => true, 
                '__experimentalDefaultControls' => array( 
                    'fontSize' => true, 
                ), 
            ), 
            'color'      => array( 
                'gradients'                     => true, 
                'link'                          => true, 
                '__experimentalDefaultControls' => array( 
                    'background' => true, 
                    'text'       => true, 
                ), 
            ), 
            'inserter'   => false, 
        ), 
        'style'             => array( 
            'wp-block-post-comments', 
            'wp-block-buttons', 
            'wp-block-button', 
        ), 
        'render_callback'   => 'render_block_core_comments', 
        'skip_inner_blocks' => true, 
    ); 
 
    /* 
     * Filters the metadata object, the same way it's done inside 
     * `register_block_type_from_metadata()`. This applies some default filters, 
     * like `_wp_multiple_block_styles`, which is required in this case because 
     * the block has multiple styles. 
     */ 
    /** This filter is documented in wp-includes/blocks.php */ 
    $metadata = apply_filters( 'block_type_metadata', $metadata ); 
 
    register_block_type( 'core/post-comments', $metadata ); 
} 
add_action( 'init', 'register_legacy_post_comments_block', 21 ); 
 
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