Use textarea instead of block preview

gutenberg.php

@@ -191,36 +191,6 @@ function gutenberg_register_widgets() {
 	}
 
 	register_widget( 'WP_Widget_Block' );
-	// By default every widget on widgets.php is wrapped with a <form>.
-	// This means that you can sometimes end up with invalid HTML, e.g. when
-	// one of the widgets is a Search block.
-	//
-	// To fix the problem, let's add a filter that moves the form below the actual
-	// widget content.
-	global $pagenow;
-	if ( 'widgets.php' === $pagenow ) {
-		add_filter(
-			'dynamic_sidebar_params',
-			'gutenberg_override_sidebar_params_for_block_widget'
-		);
-	}
-}
-
-/**
- * Overrides dynamic_sidebar_params to make sure Blocks are not wrapped in <form> tag.
- *
- * @param  array $arg Dynamic sidebar params.
- * @return array Updated dynamic sidebar params.
- */
-function gutenberg_override_sidebar_params_for_block_widget( $arg ) {
-	if ( 'Block' === $arg[0]['widget_name'] ) {
-		$arg[0]['before_form']           = '';
-		$arg[0]['before_widget_content'] = '<div class="widget-content">';
-		$arg[0]['after_widget_content']  = '</div><form class="block-widget-form">';
-		$arg[0]['after_form']            = '</form>';
-	}
-
-	return $arg;
 }
 
 add_action( 'widgets_init', 'gutenberg_register_widgets' );

lib/class-wp-widget-block.php

@@ -80,9 +80,8 @@ public function update( $new_instance, $old_instance ) {
 	 */
 	public function form( $instance ) {
 		$instance = wp_parse_args( (array) $instance, $this->default_instance );
-		echo do_blocks( $instance['content'] );
 		?>
-		<textarea id="<?php echo $this->get_field_id( 'content' ); ?>" name="<?php echo $this->get_field_name( 'content' ); ?>"  class="content sync-input" hidden><?php echo esc_textarea( $instance['content'] ); ?></textarea>
+		<textarea id="<?php echo $this->get_field_id( 'content' ); ?>" name="<?php echo $this->get_field_name( 'content' ); ?>" class="widefat text wp-block-textarea"><?php echo esc_textarea( $instance['content'] ); ?></textarea>
 		<?php
 	}
 

lib/widgets-page.php

@@ -41,7 +41,7 @@ function gutenberg_widgets_init( $hook ) {
 		wp_enqueue_style( 'wp-block-library-theme' );
 		wp_add_inline_style(
 			'wp-block-library-theme',
-			'.block-widget-form .widget-control-save { display: none; }'
+			'.wp-block-textarea { width: 100%; min-height: 5em; margin: 8px 0 16px 0; }'
 		);
 		return;
 	}