diff --git a/src/wp-includes/class-walker-comment.php b/src/wp-includes/class-walker-comment.php
index 3d2eb012e4903..1c0c98795500e 100644
--- a/src/wp-includes/class-walker-comment.php
+++ b/src/wp-includes/class-walker-comment.php
@@ -185,6 +185,19 @@ public function start_el( &$output, $data_object, $depth = 0, $args = array(), $
return;
}
+ /*
+ * Allow a registered comment type to render itself. An explicit `callback`
+ * argument passed to wp_list_comments() takes precedence and is handled above.
+ */
+ $comment_type_object = get_comment_type_object( $comment->comment_type );
+
+ if ( $comment_type_object && is_callable( $comment_type_object->render_callback ) ) {
+ ob_start();
+ call_user_func( $comment_type_object->render_callback, $comment, $args, $depth );
+ $output .= ob_get_clean();
+ return;
+ }
+
if ( 'comment' === $comment->comment_type ) {
add_filter( 'comment_text', array( $this, 'filter_comment_text' ), 40, 2 );
}
diff --git a/src/wp-includes/class-wp-comment-type.php b/src/wp-includes/class-wp-comment-type.php
index 6f88c5e7b499d..a8c0463eb16d7 100644
--- a/src/wp-includes/class-wp-comment-type.php
+++ b/src/wp-includes/class-wp-comment-type.php
@@ -104,6 +104,21 @@ final class WP_Comment_Type {
*/
public $_builtin = false;
+ /**
+ * Callback used to render a comment of this type in comment lists.
+ *
+ * When set to a callable, {@see Walker_Comment} invokes it to render a
+ * comment of this type, receiving the same arguments as the `callback`
+ * argument of wp_list_comments(): the comment object, the arguments array,
+ * and the depth. An explicit `callback` passed to wp_list_comments() still
+ * takes precedence. Output from the callback is printed unescaped; the
+ * callback is responsible for escaping all output. Default null.
+ *
+ * @since 7.1.0
+ * @var callable|null
+ */
+ public $render_callback = null;
+
/**
* Whether the comment type is hierarchical.
*
@@ -187,12 +202,13 @@ public function set_props( $args ) {
* treated as a provided value and overwrite the default name with false.
*/
$defaults = array(
- 'labels' => array(),
- 'description' => '',
- 'public' => true,
- 'internal' => false,
- 'show_ui' => null,
- '_builtin' => false,
+ 'labels' => array(),
+ 'description' => '',
+ 'public' => true,
+ 'internal' => false,
+ 'show_ui' => null,
+ 'render_callback' => null,
+ '_builtin' => false,
);
$args = array_merge( $defaults, $args );
diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index 2ebc55a1804b0..4e3f6f58f0996 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -365,8 +365,14 @@ function create_initial_comment_types() {
* the admin interface or by front-end users. Default true.
* @type bool $internal Whether the comment type is for internal use only and should be
* excluded from default public-facing contexts. Default false.
- * @type bool $show_ui Whether to generate and allow a UI for managing this comment type
- * in the admin. Default is value of $public.
+ * @type bool $show_ui Whether to generate and allow a UI for managing this comment
+ * type in the admin. Default is value of $public.
+ * @type callable $render_callback Callback used to render a comment of this type in comment
+ * lists. Receives the same arguments as the `callback` argument
+ * of wp_list_comments() (the comment, the arguments, and the
+ * depth). An explicit wp_list_comments() `callback` takes
+ * precedence. Output is printed unescaped; the callback must
+ * escape all output. Default null.
* }
* @return WP_Comment_Type|WP_Error The registered comment type object on success,
* WP_Error object on failure.
diff --git a/tests/phpunit/tests/comment/walker.php b/tests/phpunit/tests/comment/walker.php
index 504c5e3b0f2a9..434b2c12b3d38 100644
--- a/tests/phpunit/tests/comment/walker.php
+++ b/tests/phpunit/tests/comment/walker.php
@@ -54,6 +54,185 @@ public function test_has_children() {
array( $comment_child, $comment_parent )
);
}
+
+ /**
+ * Renders the comments on the test post and returns the markup.
+ *
+ * @param array $comments Comments to render.
+ * @return string Rendered markup.
+ */
+ private function render_comments( $comments, $args = array() ) {
+ return wp_list_comments(
+ array_merge(
+ array(
+ 'echo' => false,
+ 'walker' => new Walker_Comment(),
+ ),
+ $args
+ ),
+ $comments
+ );
+ }
+
+ /**
+ * A registered comment type's render_callback is used to render its comments.
+ *
+ * @ticket 35214
+ */
+ public function test_render_callback_renders_registered_comment_type() {
+ register_comment_type(
+ 'review',
+ array(
+ 'render_callback' => static function ( $comment ) {
+ echo '' . esc_html( $comment->comment_content ) . '';
+ },
+ )
+ );
+
+ $comment_id = self::factory()->comment->create(
+ array(
+ 'comment_post_ID' => $this->post_id,
+ 'comment_type' => 'review',
+ 'comment_content' => 'Rendered by callback',
+ 'comment_approved' => '1',
+ )
+ );
+
+ $output = $this->render_comments( array( get_comment( $comment_id ) ) );
+
+ $this->assertStringContainsString( 'class="review"', $output );
+ $this->assertStringContainsString( 'Rendered by callback', $output );
+
+ unregister_comment_type( 'review' );
+ }
+
+ /**
+ * An explicit wp_list_comments() callback takes precedence over a type's render_callback.
+ *
+ * @ticket 35214
+ */
+ public function test_explicit_callback_takes_precedence_over_render_callback() {
+ register_comment_type(
+ 'review',
+ array(
+ 'render_callback' => static function () {
+ echo 'FROM_TYPE_CALLBACK';
+ },
+ )
+ );
+
+ $comment_id = self::factory()->comment->create(
+ array(
+ 'comment_post_ID' => $this->post_id,
+ 'comment_type' => 'review',
+ 'comment_approved' => '1',
+ )
+ );
+
+ $output = $this->render_comments(
+ array( get_comment( $comment_id ) ),
+ array(
+ 'callback' => static function () {
+ echo 'FROM_LIST_CALLBACK';
+ },
+ )
+ );
+
+ $this->assertStringContainsString( 'FROM_LIST_CALLBACK', $output );
+ $this->assertStringNotContainsString( 'FROM_TYPE_CALLBACK', $output );
+
+ unregister_comment_type( 'review' );
+ }
+
+ /**
+ * Built-in comment types without a render_callback render normally.
+ *
+ * @ticket 35214
+ */
+ public function test_comment_type_without_render_callback_renders_normally() {
+ $comment_id = self::factory()->comment->create(
+ array(
+ 'comment_post_ID' => $this->post_id,
+ 'comment_type' => 'comment',
+ 'comment_content' => 'A normal comment',
+ 'comment_approved' => '1',
+ )
+ );
+
+ $output = $this->render_comments( array( get_comment( $comment_id ) ) );
+
+ $this->assertStringContainsString( 'A normal comment', $output );
+ }
+
+ /**
+ * The render_callback receives the comment, the arguments array, and the depth,
+ * matching the wp_list_comments() `callback` contract.
+ *
+ * @ticket 35214
+ */
+ public function test_render_callback_receives_comment_args_and_depth() {
+ $received = array();
+
+ register_comment_type(
+ 'review',
+ array(
+ 'render_callback' => static function ( $comment, $args, $depth ) use ( &$received ) {
+ $received = array(
+ 'comment' => $comment,
+ 'args' => $args,
+ 'depth' => $depth,
+ );
+ echo '';
+ },
+ )
+ );
+
+ $comment_id = self::factory()->comment->create(
+ array(
+ 'comment_post_ID' => $this->post_id,
+ 'comment_type' => 'review',
+ 'comment_approved' => '1',
+ )
+ );
+
+ $this->render_comments( array( get_comment( $comment_id ) ) );
+
+ $this->assertInstanceOf( 'WP_Comment', $received['comment'], 'The callback should receive the comment object.' );
+ $this->assertSame( (string) $comment_id, (string) $received['comment']->comment_ID, 'The callback should receive the rendered comment.' );
+ $this->assertIsArray( $received['args'], 'The callback should receive the arguments array.' );
+ $this->assertSame( 1, $received['depth'], 'A top-level comment should be rendered at depth 1.' );
+
+ unregister_comment_type( 'review' );
+ }
+
+ /**
+ * A render_callback that is not callable is ignored and the comment renders normally.
+ *
+ * @ticket 35214
+ */
+ public function test_non_callable_render_callback_is_ignored() {
+ register_comment_type(
+ 'review',
+ array(
+ 'render_callback' => 'this_is_not_a_callable_function',
+ )
+ );
+
+ $comment_id = self::factory()->comment->create(
+ array(
+ 'comment_post_ID' => $this->post_id,
+ 'comment_type' => 'review',
+ 'comment_content' => 'Falls back to normal rendering',
+ 'comment_approved' => '1',
+ )
+ );
+
+ $output = $this->render_comments( array( get_comment( $comment_id ) ) );
+
+ $this->assertStringContainsString( 'Falls back to normal rendering', $output );
+
+ unregister_comment_type( 'review' );
+ }
}
class Comment_Callback_Test_Helper {
diff --git a/tests/phpunit/tests/comment/wpCommentType.php b/tests/phpunit/tests/comment/wpCommentType.php
index bf6d3c7df28dd..9dd8c3a37187b 100644
--- a/tests/phpunit/tests/comment/wpCommentType.php
+++ b/tests/phpunit/tests/comment/wpCommentType.php
@@ -24,6 +24,19 @@ public function test_instance_defaults() {
$this->assertFalse( $comment_type->_builtin );
$this->assertTrue( $comment_type->show_ui );
$this->assertFalse( $comment_type->hierarchical );
+ $this->assertNull( $comment_type->render_callback );
+ }
+
+ /**
+ * @ticket 35214
+ *
+ * @covers ::set_props
+ */
+ public function test_render_callback_is_stored() {
+ $callback = static function () {};
+ $comment_type = new WP_Comment_Type( 'foo', array( 'render_callback' => $callback ) );
+
+ $this->assertSame( $callback, $comment_type->render_callback );
}
/**