Changeset 57514 for trunk/src/wp-includes/class-wp-block.php

Timestamp:

02/01/2024 12:52:54 PM (8 months ago)

Author:

youknowriad

Message:

Editor: Add the Block Bindings API.

This introduces the Block Bindings API for WordPress.

The API allows developers to connects block attributes to different sources. In this PR, two such sources are included: "post meta" and "pattern". Attributes connected to sources can have their HTML replaced by values coming from the source in a way defined by the binding.

Props czapla, lgladdy, gziolo, sc0ttkclark, swissspidy, artemiosans, kevin940726, fabiankaegy, santosguillamot, talldanwp, wildworks.
Fixes #60282.

File:

• trunk/src/wp-includes/class-wp-block.php (modified) (2 diffs)

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

@@ -193 +193 @@
 
     /**
+     * Processes the block bindings in block's attributes.
+     *
+     * 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.
+     *
+     * ### Example
+     *
+     * The "bindings" property for an Image block might look like this:
+     *
+     * ```json
+     * {
+     *   "metadata": {
+     *     "bindings": {
+     *       "title": {
+     *         "source": "post_meta",
+     *         "args": { "key": "text_custom_field" }
+     *       },
+     *       "url": {
+     *         "source": "post_meta",
+     *         "args": { "key": "url_custom_field" }
+     *       }
+     *     }
+     *   }
+     * }
+     * ```
+     *
+     * The above example will replace the `title` and `url` attributes of the Image
+     * block with the values of the `text_custom_field` and `url_custom_field` post meta.
+     *
+     * @access private
+     * @since 6.5.0
+     *
+     * @param string   $block_content Block content.
+     * @param array    $block The full block, including name and attributes.
+     */
+    private function process_block_bindings( $block_content ) {
+        $block = $this->parsed_block;
+
+        // 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(
+            'core/paragraph' => array( 'content' ),
+            'core/heading'   => array( 'content' ),
+            'core/image'     => array( 'url', 'title', 'alt' ),
+            'core/button'    => array( 'url', 'text' ),
+        );
+
+        // If the block doesn't have the bindings property, isn't one of the allowed
+        // block types, or the bindings property is not an array, return the block content.
+        if ( ! isset( $block['attrs']['metadata']['bindings'] ) ||
+                ! is_array( $block['attrs']['metadata']['bindings'] ) ||
+                ! isset( $allowed_blocks[ $this->name ] )
+                ) {
+            return $block_content;
+        }
+
+        $block_bindings_sources = get_all_registered_block_bindings_sources();
+        $modified_block_content = $block_content;
+        foreach ( $block['attrs']['metadata']['bindings'] as $binding_attribute => $binding_source ) {
+            // If the attribute is not in the list, process next attribute.
+            if ( ! in_array( $binding_attribute, $allowed_blocks[ $this->name ], true ) ) {
+                continue;
+            }
+            // If no source is provided, or that source is not registered, process next attribute.
+            if ( ! isset( $binding_source['source'] ) || ! is_string( $binding_source['source'] ) || ! isset( $block_bindings_sources[ $binding_source['source'] ] ) ) {
+                continue;
+            }
+
+            $source_callback = $block_bindings_sources[ $binding_source['source'] ]['get_value_callback'];
+            // Get the value based on the source.
+            if ( ! isset( $binding_source['args'] ) ) {
+                $source_args = array();
+            } else {
+                $source_args = $binding_source['args'];
+            }
+            $source_value = call_user_func_array( $source_callback, array( $source_args, $this, $binding_attribute ) );
+            // If the value is null, process next attribute.
+            if ( is_null( $source_value ) ) {
+                continue;
+            }
+
+            // Process the HTML based on the block and the attribute.
+            $modified_block_content = $this->replace_html( $modified_block_content, $this->name, $binding_attribute, $source_value );
+        }
+        return $modified_block_content;
+    }
+
+    /**
+     * Depending on the block attributes, replace the HTML based on the value returned by the source.
+     *
+     * @since 6.5.0
+     *
+     * @param string $block_content Block content.
+     * @param string $block_name The name of the block to process.
+     * @param string $block_attr The attribute of the block we want to process.
+     * @param string $source_value The value used to replace the HTML.
+     */
+    private function replace_html( string $block_content, string $block_name, string $block_attr, string $source_value ) {
+        $block_type = $this->block_type;
+        if ( null === $block_type || ! isset( $block_type->attributes[ $block_attr ] ) ) {
+            return $block_content;
+        }
+
+        // Depending on the attribute source, the processing will be different.
+        switch ( $block_type->attributes[ $block_attr ]['source'] ) {
+            case 'html':
+            case 'rich-text':
+                $block_reader = new WP_HTML_Tag_Processor( $block_content );
+
+                // TODO: Support for CSS selectors whenever they are ready in the HTML API.
+                // In the meantime, support comma-separated selectors by exploding them into an array.
+                $selectors = explode( ',', $block_type->attributes[ $block_attr ]['selector'] );
+                // Add a bookmark to the first tag to be able to iterate over the selectors.
+                $block_reader->next_tag();
+                $block_reader->set_bookmark( 'iterate-selectors' );
+
+                // TODO: This shouldn't be needed when the `set_inner_html` function is ready.
+                // Store the parent tag and its attributes to be able to restore them later in the button.
+                // The button block has a wrapper while the paragraph and heading blocks don't.
+                if ( 'core/button' === $block_name ) {
+                    $button_wrapper                 = $block_reader->get_tag();
+                    $button_wrapper_attribute_names = $block_reader->get_attribute_names_with_prefix( '' );
+                    $button_wrapper_attrs           = array();
+                    foreach ( $button_wrapper_attribute_names as $name ) {
+                        $button_wrapper_attrs[ $name ] = $block_reader->get_attribute( $name );
+                    }
+                }
+
+                foreach ( $selectors as $selector ) {
+                    // If the parent tag, or any of its children, matches the selector, replace the HTML.
+                    if ( strcasecmp( $block_reader->get_tag( $selector ), $selector ) === 0 || $block_reader->next_tag(
+                        array(
+                            'tag_name' => $selector,
+                        )
+                    ) ) {
+                        $block_reader->release_bookmark( 'iterate-selectors' );
+
+                        // TODO: Use `set_inner_html` method whenever it's ready in the HTML API.
+                        // Until then, it is hardcoded for the paragraph, heading, and button blocks.
+                        // Store the tag and its attributes to be able to restore them later.
+                        $selector_attribute_names = $block_reader->get_attribute_names_with_prefix( '' );
+                        $selector_attrs           = array();
+                        foreach ( $selector_attribute_names as $name ) {
+                            $selector_attrs[ $name ] = $block_reader->get_attribute( $name );
+                        }
+                        $selector_markup = "<$selector>" . wp_kses_post( $source_value ) . "</$selector>";
+                        $amended_content = new WP_HTML_Tag_Processor( $selector_markup );
+                        $amended_content->next_tag();
+                        foreach ( $selector_attrs as $attribute_key => $attribute_value ) {
+                            $amended_content->set_attribute( $attribute_key, $attribute_value );
+                        }
+                        if ( 'core/paragraph' === $block_name || 'core/heading' === $block_name ) {
+                            return $amended_content->get_updated_html();
+                        }
+                        if ( 'core/button' === $block_name ) {
+                            $button_markup  = "<$button_wrapper>{$amended_content->get_updated_html()}</$button_wrapper>";
+                            $amended_button = new WP_HTML_Tag_Processor( $button_markup );
+                            $amended_button->next_tag();
+                            foreach ( $button_wrapper_attrs as $attribute_key => $attribute_value ) {
+                                $amended_button->set_attribute( $attribute_key, $attribute_value );
+                            }
+                            return $amended_button->get_updated_html();
+                        }
+                    } else {
+                        $block_reader->seek( 'iterate-selectors' );
+                    }
+                }
+                $block_reader->release_bookmark( 'iterate-selectors' );
+                return $block_content;
+
+            case 'attribute':
+                $amended_content = new WP_HTML_Tag_Processor( $block_content );
+                if ( ! $amended_content->next_tag(
+                    array(
+                        // TODO: build the query from CSS selector.
+                        'tag_name' => $block_type->attributes[ $block_attr ]['selector'],
+                    )
+                ) ) {
+                    return $block_content;
+                }
+                $amended_content->set_attribute( $block_type->attributes[ $block_attr ]['attribute'], esc_attr( $source_value ) );
+                return $amended_content->get_updated_html();
+                break;
+
+            default:
+                return $block_content;
+                break;
+        }
+        return;
+    }
+
+
+    /**
      * Generates the render output for the block.
      *
@@ -286 +484 @@
             }
         }
+
+        // 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 );
 
         /**