1<?php
  2/**
  3 * Server-side rendering of the `core/comments` block.
  4 *
  5 * @package WordPress
  6 */
  7
  8/**
  9 * Renders the `core/comments` block on the server.
 10 *
 11 * This render callback is mainly for rendering a dynamic, legacy version of
 12 * this block (the old `core/post-comments`). It uses the `comments_template()`
 13 * function to generate the output, in the same way as classic PHP themes.
 14 *
 15 * As this callback will always run during SSR, first we need to check whether
 16 * the block is in legacy mode. If not, the HTML generated in the editor is
 17 * returned instead.
 18 *
 19 * @since 6.1.0
 20 *
 21 * @global WP_Post $post Global post object.
 22 *
 23 * @param array    $attributes Block attributes.
 24 * @param string   $content    Block default content.
 25 * @param WP_Block $block      Block instance.
 26 * @return string Returns the filtered post comments for the current post wrapped inside "p" tags.
 27 */
 28function render_block_core_comments( $attributes, $content, $block ) {
 29	global $post;
 30
 31	if ( ! isset( $block->context['postId'] ) ) {
 32		return '';
 33	}
 34
 35	$post_id = $block->context['postId'];
 36	// Return early if there are no comments and comments are closed.
 37	if ( ! comments_open( $post_id ) && (int) get_comments_number( $post_id ) === 0 ) {
 38		return '';
 39	}
 40
 41	// If this isn't the legacy block, we need to render the static version of this block.
 42	$is_legacy = 'core/post-comments' === $block->name || ! empty( $attributes['legacy'] );
 43	if ( ! $is_legacy ) {
 44		return $block->render( array( 'dynamic' => false ) );
 45	}
 46
 47	$post_before = $post;
 48	$post        = get_post( $post_id );
 49	setup_postdata( $post );
 50
 51	ob_start();
 52
 53	/*
 54	 * There's a deprecation warning generated by WP Core.
 55	 * Ideally this deprecation is removed from Core.
 56	 * In the meantime, this removes it from the output.
 57	 */
 58	add_filter( 'deprecated_file_trigger_error', '__return_false' );
 59	comments_template();
 60	remove_filter( 'deprecated_file_trigger_error', '__return_false' );
 61
 62	$output = ob_get_clean();
 63	$post   = $post_before;
 64
 65	$classnames = array();
 66	// Adds the old class name for styles' backwards compatibility.
 67	if ( isset( $attributes['legacy'] ) ) {
 68		$classnames[] = 'wp-block-post-comments';
 69	}
 70	if ( isset( $attributes['textAlign'] ) ) {
 71		$classnames[] = 'has-text-align-' . $attributes['textAlign'];
 72	}
 73
 74	$wrapper_attributes = get_block_wrapper_attributes(
 75		array( 'class' => implode( ' ', $classnames ) )
 76	);
 77
 78	/*
 79	 * Enqueues scripts and styles required only for the legacy version. That is
 80	 * why they are not defined in `block.json`.
 81	 */
 82	wp_enqueue_script( 'comment-reply' );
 83	enqueue_legacy_post_comments_block_styles( $block->name );
 84
 85	return sprintf( '<div %1$s>%2$s</div>', $wrapper_attributes, $output );
 86}
 87
 88/**
 89 * Registers the `core/comments` block on the server.
 90 *
 91 * @since 6.1.0
 92 */
 93function register_block_core_comments() {
 94	register_block_type_from_metadata(
 95		__DIR__ . '/comments',
 96		array(
 97			'render_callback'   => 'render_block_core_comments',
 98			'skip_inner_blocks' => true,
 99		)
100	);
101}
102add_action( 'init', 'register_block_core_comments' );
103
104/**
105 * Use the button block classes for the form-submit button.
106 *
107 * @since 6.1.0
108 *
109 * @param array $fields The default comment form arguments.
110 *
111 * @return array Returns the modified fields.
112 */
113function comments_block_form_defaults( $fields ) {
114	if ( wp_is_block_theme() ) {
115		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s wp-block-button__link ' . wp_theme_get_element_class_name( 'button' ) . '" value="%4$s" />';
116		$fields['submit_field']  = '<p class="form-submit wp-block-button">%1$s %2$s</p>';
117	}
118
119	return $fields;
120}
121add_filter( 'comment_form_defaults', 'comments_block_form_defaults' );
122
123/**
124 * Enqueues styles from the legacy `core/post-comments` block. These styles are
125 * required only by the block's fallback.
126 *
127 * @since 6.1.0
128 *
129 * @param string $block_name Name of the new block type.
130 */
131function enqueue_legacy_post_comments_block_styles( $block_name ) {
132	static $are_styles_enqueued = false;
133
134	if ( ! $are_styles_enqueued ) {
135		$handles = array(
136			'wp-block-post-comments',
137			'wp-block-buttons',
138			'wp-block-button',
139		);
140		foreach ( $handles as $handle ) {
141			wp_enqueue_block_style( $block_name, array( 'handle' => $handle ) );
142		}
143		$are_styles_enqueued = true;
144	}
145}
146
147/**
148 * Ensures backwards compatibility for any users running the Gutenberg plugin
149 * who have used Post Comments before it was merged into Comments Query Loop.
150 *
151 * The same approach was followed when core/query-loop was renamed to
152 * core/post-template.
153 *
154 * @since 6.1.0
155 *
156 * @see https://github.com/WordPress/gutenberg/pull/41807
157 * @see https://github.com/WordPress/gutenberg/pull/32514
158 */
159function register_legacy_post_comments_block() {
160	$registry = WP_Block_Type_Registry::get_instance();
161
162	/*
163	 * Remove the old `post-comments` block if it was already registered, as it
164	 * is about to be replaced by the type defined below.
165	 */
166	if ( $registry->is_registered( 'core/post-comments' ) ) {
167		unregister_block_type( 'core/post-comments' );
168	}
169
170	// Recreate the legacy block metadata.
171	$metadata = array(
172		'name'              => 'core/post-comments',
173		'category'          => 'theme',
174		'attributes'        => array(
175			'textAlign' => array(
176				'type' => 'string',
177			),
178		),
179		'uses_context'      => array(
180			'postId',
181			'postType',
182		),
183		'supports'          => array(
184			'html'       => false,
185			'align'      => array( 'wide', 'full' ),
186			'typography' => array(
187				'fontSize'                      => true,
188				'lineHeight'                    => true,
189				'__experimentalFontStyle'       => true,
190				'__experimentalFontWeight'      => true,
191				'__experimentalLetterSpacing'   => true,
192				'__experimentalTextTransform'   => true,
193				'__experimentalDefaultControls' => array(
194					'fontSize' => true,
195				),
196			),
197			'color'      => array(
198				'gradients'                     => true,
199				'link'                          => true,
200				'__experimentalDefaultControls' => array(
201					'background' => true,
202					'text'       => true,
203				),
204			),
205			'inserter'   => false,
206		),
207		'style'             => array(
208			'wp-block-post-comments',
209			'wp-block-buttons',
210			'wp-block-button',
211		),
212		'render_callback'   => 'render_block_core_comments',
213		'skip_inner_blocks' => true,
214	);
215
216	/*
217	 * Filters the metadata object, the same way it's done inside
218	 * `register_block_type_from_metadata()`. This applies some default filters,
219	 * like `_wp_multiple_block_styles`, which is required in this case because
220	 * the block has multiple styles.
221	 */
222	/** This filter is documented in wp-includes/blocks.php */
223	$metadata = apply_filters( 'block_type_metadata', $metadata );
224
225	register_block_type( 'core/post-comments', $metadata );
226}
227add_action( 'init', 'register_legacy_post_comments_block', 21 );
228