Refactor block binding processing and attribute computation

src/wp-includes/class-wp-block.php

@@ -230,11 +230,13 @@ public function __get( $name ) {
 	 *
 	 * @param string $block_content Block content.
 	 * @param array  $block         The full block, including name and attributes.
-	 * @return string The modified block content.
+	 * @return array The modified block content.
 	 */
-	private function process_block_bindings( $block_content ) {
+	private function process_block_bindings() {
 		$parsed_block = $this->parsed_block;
 
+		$computed_attributes = array();
+
 		// Allowed blocks that support block bindings.
 		// TODO: Look for a mechanism to opt-in for this. Maybe adding a property to block attributes?
 		$allowed_blocks = array(
@@ -251,10 +253,9 @@ private function process_block_bindings( $block_content ) {
 			empty( $parsed_block['attrs']['metadata']['bindings'] ) ||
 			! is_array( $parsed_block['attrs']['metadata']['bindings'] )
 		) {
-			return $block_content;
+			return $computed_attributes;
 		}
 
-		$modified_block_content = $block_content;
 		foreach ( $parsed_block['attrs']['metadata']['bindings'] as $attribute_name => $block_binding ) {
 			// If the attribute is not in the allowed list, process next attribute.
 			if ( ! in_array( $attribute_name, $allowed_blocks[ $this->name ], true ) ) {
@@ -276,11 +277,11 @@ private function process_block_bindings( $block_content ) {
 
 			// If the value is not null, process the HTML based on the block and the attribute.
 			if ( ! is_null( $source_value ) ) {
-				$modified_block_content = $this->replace_html( $modified_block_content, $attribute_name, $source_value );
+				$computed_attributes[ $attribute_name ] = $source_value;
 			}
 		}
 
-		return $modified_block_content;
+		return $computed_attributes;
 	}
 
 	/**
@@ -446,6 +447,19 @@ public function render( $options = array() ) {
 			}
 		}
 
+		$computed_attributes = $this->process_block_bindings();
+
+		// If there are computed attributes, update the attributes with the
+		// computed ones.
+		if ( ! empty( $computed_attributes ) ) {
+			// Merge the computed attributes with the original attributes
+			$this->attributes = array_merge( $this->attributes, $computed_attributes );
+		}
+
+		foreach ( $computed_attributes as $attribute_name => $source_value ) {
+			$block_content = $this->replace_html( $block_content, $attribute_name, $source_value );
+		}
+
 		if ( $is_dynamic ) {
 			$global_post = $post;
 			$parent      = WP_Block_Supports::$block_to_render;
@@ -483,10 +497,6 @@ public function render( $options = array() ) {
 			}
 		}
 
-		// Process the block bindings for this block, if any are registered. This
-		// will replace the block content with the value from a registered binding source.
-		$block_content = $this->process_block_bindings( $block_content );
-
 		/**
 		 * Filters the content of a single block.
 		 *