Widget block: Add `widget_block_content` filter

Adds a new 'widget_block_content' filter to the widget block and hooks
`run_shortcode`, `autoembed`, `do_blocks`, and `do_shortcode` into it by
default. This is simlar to `widget_text_content.`

Fixes #51566.
Props talldanwp.

Built from https://develop.svn.wordpress.org/trunk@51058


git-svn-id: http://core.svn.wordpress.org/trunk@50667 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-embed.php

@@ -31,6 +31,7 @@ class WP_Embed {
 		// Hack to get the [embed] shortcode to run before wpautop().
 		add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );
 		add_filter( 'widget_text_content', array( $this, 'run_shortcode' ), 8 );
+		add_filter( 'widget_block_content', array( $this, 'run_shortcode' ), 8 );
 
 		// Shortcode placeholder for strip_shortcodes().
 		add_shortcode( 'embed', '__return_false' );
@@ -38,6 +39,7 @@ class WP_Embed {
 		// Attempts to embed all URLs in a post.
 		add_filter( 'the_content', array( $this, 'autoembed' ), 8 );
 		add_filter( 'widget_text_content', array( $this, 'autoembed' ), 8 );
+		add_filter( 'widget_block_content', array( $this, 'autoembed' ), 8 );
 
 		// After a post is saved, cache oEmbed items via Ajax.
 		add_action( 'edit_form_advanced', array( $this, 'maybe_run_ajax_cache' ) );

wp-includes/default-filters.php

@@ -214,6 +214,9 @@ add_filter( 'widget_text_content', 'wp_filter_content_tags' );
 add_filter( 'widget_text_content', 'wp_replace_insecure_home_url' );
 add_filter( 'widget_text_content', 'do_shortcode', 11 ); // Runs after wpautop(); note that $post global will be null when shortcodes run.
 
+add_filter( 'widget_block_content', 'do_blocks', 9 );
+add_filter( 'widget_block_content', 'do_shortcode', 11 );
+
 add_filter( 'wp_get_custom_css', 'wp_replace_insecure_home_url' );
 
 // RSS filters.

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-51057';
+$wp_version = '5.8-alpha-51058';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-includes/widgets/class-wp-widget-block.php

@@ -66,20 +66,21 @@ class WP_Widget_Block extends WP_Widget {
 			$args['before_widget']
 		);
 
-		// Handle embeds for block widgets.
-		//
-		// When this feature is added to core it may need to be implemented
-		// differently. WP_Widget_Text is a good reference, that applies a
-		// filter for its content, which WP_Embed uses in its constructor.
-		// See https://core.trac.wordpress.org/ticket/51566.
-		global $wp_embed;
-		$content = $wp_embed->run_shortcode( $instance['content'] );
-		$content = $wp_embed->autoembed( $content );
-
-		$content = do_blocks( $content );
-		$content = do_shortcode( $content );
-
-		echo $content;
+		/**
+		 * Filters the content of the Block widget before output.
+		 *
+		 * @since 5.8.0
+		 *
+		 * @param string         $content  The widget content.
+		 * @param array          $instance Array of settings for the current widget.
+		 * @param WP_Widget_Text $widget   Current Block widget instance.
+		 */
+		echo apply_filters(
+			'widget_block_content',
+			$instance['content'],
+			$instance,
+			$this
+		);
 
 		echo $args['after_widget'];
 	}