Refactor block binding processing and attribute computation

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

@@ -192,15 +192,15 @@ public function __get( $name ) {
 	}
 
 	/**
-	 * Processes the block bindings in block's attributes.
+	 * Processes the block bindings and updates the block attributes with the values from the sources.
 	 *
 	 * A block might contain bindings in its attributes. Bindings are mappings
 	 * between an attribute of the block and a source. A "source" is a function
 	 * registered with `register_block_bindings_source()` that defines how to
 	 * retrieve a value from outside the block, e.g. from post meta.
 	 *
-	 * This function will process those bindings and replace the HTML with the value of the binding.
-	 * The value is retrieved from the source of the binding.
+	 * This function will process those bindings and update the block's attributes
+	 * with the values coming from the bindings.
 	 *
 	 * ### Example
 	 *
@@ -228,13 +228,13 @@ public function __get( $name ) {
 	 *
 	 * @since 6.5.0
 	 *
-	 * @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 computed block attributes for the provided block bindings.
 	 */
-	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 +251,9 @@ 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 ) ) {
@@ -275,11 +274,18 @@ 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;
+		// 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 );
+		}
+
+		return $computed_attributes;
 	}
 
 	/**
@@ -410,6 +416,9 @@ public function render( $options = array() ) {
 			)
 		);
 
+		// Process the block bindings and get attributes updated with the values from the sources.
+		$computed_attributes = $this->process_block_bindings();
+
 		$is_dynamic    = $options['dynamic'] && $this->name && null !== $this->block_type && $this->block_type->is_dynamic();
 		$block_content = '';
 
@@ -445,6 +454,12 @@ public function render( $options = array() ) {
 			}
 		}
 
+		if ( ! empty( $computed_attributes ) && ! empty( $block_content ) ) {
+			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;
@@ -488,10 +503,6 @@ 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.
 		 *

tests/phpunit/tests/block-bindings/render.php

@@ -62,6 +62,7 @@ public function test_update_block_with_value_from_source() {
 		$result   = $block->render();
 
 		$this->assertEquals( $expected, $result, 'The block content should be updated with the value returned by the source.' );
+		$this->assertSame( 'test source value', $block->attributes['content'] );
 	}
 
 	/**
@@ -97,5 +98,44 @@ public function test_passing_arguments_to_source() {
 		$result   = $block->render();
 
 		$this->assertEquals( $expected, $result, 'The block content should be updated with the value returned by the source.' );
+		$this->assertSame( "The attribute name is 'content' and its binding has argument 'key' with value '$value'.", $block->attributes['content'] );
+	}
+
+
+	/**
+	 * Tests if the block content is updated with the value returned by the source
+	 * for the Image block in the placeholder state.
+	 *
+	 * @ticket 60282
+	 *
+	 * @covers ::register_block_bindings_source
+	 */
+	public function test_update_block_with_value_from_source_imag_placeholder() {
+		$get_value_callback = function () {
+			return 'https://example.com/image.jpg';
+		};
+
+		register_block_bindings_source(
+			self::SOURCE_NAME,
+			array(
+				'label'              => self::SOURCE_LABEL,
+				'get_value_callback' => $get_value_callback,
+			)
+		);
+
+		$block_content = <<<HTML
+<!-- wp:image {"metadata":{"bindings":{"url":{"source":"test/source"}}}} -->
+<figure class="wp-block-image"><img alt=""/></figure>
+<!-- /wp:image -->
+HTML;
+
+		$parsed_blocks = parse_blocks( $block_content );
+		$block         = new WP_Block( $parsed_blocks[0] );
+
+		$expected = '<figure class="wp-block-image"><img src="https://example.com/image.jpg" alt=""/></figure>';
+		$result   = $block->render();
+
+		$this->assertSame( 'https://example.com/image.jpg', $block->attributes['url'] );
+		$this->assertEquals( $expected, trim( $result ), 'The block content should be updated with the value returned by the source.' );
 	}
 }