Add an 'area' term for Template Parts.

lib/class-wp-theme-json.php

@@ -104,6 +104,7 @@ class WP_Theme_JSON {
 	 */
 	const SCHEMA = array(
 		'customTemplates' => null,
+		'templateParts'   => null,
 		'styles'          => array(
 			'border'     => array(
 				'radius' => null,
@@ -1064,6 +1065,18 @@ public function get_custom_templates() {
 		}
 	}
 
+	/**
+	 * Returns the template part data of current theme.
+	 *
+	 * @return array
+	 */
+	public function get_template_parts() {
+		if ( ! isset( $this->theme_json['templateParts'] ) ) {
+			return array();
+		}
+		return $this->theme_json['templateParts'];
+	}
+
 	/**
 	 * Returns the stylesheet that results of processing
 	 * the theme.json structure this object represents.

lib/full-site-editing/block-templates.php

@@ -49,12 +49,17 @@ function _gutenberg_get_template_file( $template_type, $slug ) {
 	foreach ( $themes as $theme_slug => $theme_dir ) {
 		$file_path = $theme_dir . '/' . $template_base_paths[ $template_type ] . '/' . $slug . '.html';
 		if ( file_exists( $file_path ) ) {
-			return array(
+			$new_template_item = array(
 				'slug'  => $slug,
 				'path'  => $file_path,
 				'theme' => $theme_slug,
 				'type'  => $template_type,
 			);
+
+			if ( 'wp_template_part' === $template_type ) {
+				return _gutenberg_add_template_part_area_info( $new_template_item );
+			}
+			return $new_template_item;
 		}
 	}
 
@@ -93,18 +98,45 @@ function _gutenberg_get_template_files( $template_type ) {
 				// Subtract ending '.html'.
 				-5
 			);
-			$template_files[] = array(
+			$new_template_item = array(
 				'slug'  => $template_slug,
 				'path'  => $template_file,
 				'theme' => $theme_slug,
 				'type'  => $template_type,
 			);
+
+			if ( 'wp_template_part' === $template_type ) {
+				$template_files[] = _gutenberg_add_template_part_area_info( $new_template_item );
+			} else {
+				$template_files[] = $new_template_item;
+			}
 		}
 	}
 
 	return $template_files;
 }
 
+/**
+ * Attempts to add the template part's area information to the input template.
+ *
+ * @param array $template_info Template to add information to (requires 'type' and 'slug' fields).
+ *
+ * @return array Template.
+ */
+function _gutenberg_add_template_part_area_info( $template_info ) {
+	if ( WP_Theme_JSON_Resolver::theme_has_support() ) {
+		$theme_data = WP_Theme_JSON_Resolver::get_theme_data()->get_template_parts();
+	}
+
+	if ( isset( $theme_data[ $template_info['slug'] ]['area'] ) ) {
+		$template_info['area'] = gutenberg_filter_template_part_area_type( $theme_data[ $template_info['slug'] ]['area'] );
+	} else {
+		$template_info['area'] = WP_TEMPLATE_PART_AREA_UNCATEGORIZED;
+	}
+
+	return $template_info;
+}
+
 /**
  * Parses wp_template content and injects the current theme's
  * stylesheet as a theme attribute into each wp_template_part
@@ -171,6 +203,10 @@ function _gutenberg_build_template_result_from_file( $template_file, $template_t
 		$template->title       = $default_template_types[ $template_file['slug'] ]['title'];
 	}
 
+	if ( 'wp_template_part' === $template_type && isset( $template_file['area'] ) ) {
+		$template->area = $template_file['area'];
+	}
+
 	return $template;
 }
 
@@ -206,6 +242,13 @@ function _gutenberg_build_template_result_from_post( $post ) {
 	$template->title       = $post->post_title;
 	$template->status      = $post->post_status;
 
+	if ( 'wp_template_part' === $post->post_type ) {
+		$type_terms = get_the_terms( $post, 'wp_template_part_area' );
+		if ( ! is_wp_error( $type_terms ) && false !== $type_terms ) {
+			$template->area = $type_terms[0]->name;
+		}
+	}
+
 	return $template;
 }
 
@@ -237,6 +280,15 @@ function gutenberg_get_block_templates( $query = array(), $template_type = 'wp_t
 		),
 	);
 
+	if ( 'wp_template_part' === $template_type && isset( $query['area'] ) ) {
+		$wp_query_args['tax_query'][]           = array(
+			'taxonomy' => 'wp_template_part_area',
+			'field'    => 'name',
+			'terms'    => $query['area'],
+		);
+		$wp_query_args['tax_query']['relation'] = 'AND';
+	}
+
 	if ( isset( $query['slug__in'] ) ) {
 		$wp_query_args['post_name__in'] = $query['slug__in'];
 	}
@@ -261,14 +313,16 @@ function gutenberg_get_block_templates( $query = array(), $template_type = 'wp_t
 	if ( ! isset( $query['wp_id'] ) ) {
 		$template_files = _gutenberg_get_template_files( $template_type );
 		foreach ( $template_files as $template_file ) {
-			$is_custom      = array_search(
+			$is_not_custom   = false === array_search(
 				wp_get_theme()->get_stylesheet() . '//' . $template_file['slug'],
 				array_column( $query_result, 'id' ),
 				true
 			);
-			$should_include = false === $is_custom && (
-				! isset( $query['slug__in'] ) || in_array( $template_file['slug'], $query['slug__in'], true )
-			);
+			$fits_slug_query =
+				! isset( $query['slug__in'] ) || in_array( $template_file['slug'], $query['slug__in'], true );
+			$fits_area_query =
+				! isset( $query['area'] ) || $template_file['area'] === $query['area'];
+			$should_include  = $is_not_custom && $fits_slug_query && $fits_area_query;
 			if ( $should_include ) {
 				$query_result[] = _gutenberg_build_template_result_from_file( $template_file, $template_type );
 			}

lib/full-site-editing/class-wp-rest-templates-controller.php

@@ -138,6 +138,9 @@ public function get_items( $request ) {
 		if ( isset( $request['wp_id'] ) ) {
 			$query['wp_id'] = $request['wp_id'];
 		}
+		if ( isset( $request['area'] ) ) {
+			$query['area'] = $request['area'];
+		}
 		$templates = array();
 		foreach ( gutenberg_get_block_templates( $query, $this->post_type ) as $template ) {
 			$data        = $this->prepare_item_for_response( $template, $request );
@@ -358,6 +361,16 @@ protected function prepare_item_for_database( $request ) {
 			$changes->post_excerpt = $template->description;
 		}
 
+		if ( 'wp_template_part' === $this->post_type ) {
+			if ( isset( $request['area'] ) ) {
+				$changes->tax_input['wp_template_part_area'] = gutenberg_filter_template_part_area_type( $request['area'] );
+			} elseif ( null !== $template && ! $template->is_custom && $template->area ) {
+				$changes->tax_input['wp_template_part_area'] = gutenberg_filter_template_part_area_type( $template->area );
+			} elseif ( ! $template->area ) {
+				$changes->tax_input['wp_template_part_area'] = WP_TEMPLATE_PART_AREA_UNCATEGORIZED;
+			}
+		}
+
 		return $changes;
 	}
 
@@ -386,6 +399,10 @@ public function prepare_item_for_response( $template, $request ) { // phpcs:igno
 			'wp_id'       => $template->wp_id,
 		);
 
+		if ( 'wp_template_part' === $template->type ) {
+			$result['area'] = $template->area;
+		}
+
 		$result = $this->add_additional_fields_to_object( $result, $request );
 
 		$response = rest_ensure_response( $result );
@@ -536,6 +553,14 @@ public function get_item_schema() {
 			),
 		);
 
+		if ( 'wp_template_part' === $this->post_type ) {
+			$schema['properties']['area'] = array(
+				'description' => __( 'Where the template part is intended for use (header, footer, etc.)', 'gutenberg' ),
+				'type'        => 'string',
+				'context'     => array( 'embed', 'view', 'edit' ),
+			);
+		}
+
 		$this->schema = $schema;
 
 		return $this->add_additional_fields_schema( $this->schema );

lib/full-site-editing/template-parts.php

@@ -60,6 +60,49 @@ function gutenberg_register_template_part_post_type() {
 }
 add_action( 'init', 'gutenberg_register_template_part_post_type' );
 
+/**
+ * Registers the 'wp_template_part_area' taxonomy.
+ */
+function gutenberg_register_wp_template_part_area_taxonomy() {
+	if ( ! gutenberg_is_fse_theme() ) {
+		return;
+	}
+
+	register_taxonomy(
+		'wp_template_part_area',
+		array( 'wp_template_part' ),
+		array(
+			'public'            => false,
+			'hierarchical'      => false,
+			'labels'            => array(
+				'name'          => __( 'Template Part Areas', 'gutenberg' ),
+				'singular_name' => __( 'Template Part Area', 'gutenberg' ),
+			),
+			'query_var'         => false,
+			'rewrite'           => false,
+			'show_ui'           => false,
+			'_builtin'          => true,
+			'show_in_nav_menus' => false,
+			'show_in_rest'      => false,
+		)
+	);
+}
+add_action( 'init', 'gutenberg_register_wp_template_part_area_taxonomy' );
+
+// Definte constants for supported wp_template_part_area taxonomy.
+if ( ! defined( 'WP_TEMPLATE_PART_AREA_HEADER' ) ) {
+	define( 'WP_TEMPLATE_PART_AREA_HEADER', 'header' );
+}
+if ( ! defined( 'WP_TEMPLATE_PART_AREA_FOOTER' ) ) {
+	define( 'WP_TEMPLATE_PART_AREA_FOOTER', 'footer' );
+}
+if ( ! defined( 'WP_TEMPLATE_PART_AREA_SIDEBAR' ) ) {
+	define( 'WP_TEMPLATE_PART_AREA_SIDEBAR', 'sidebar' );
+}
+if ( ! defined( 'WP_TEMPLATE_PART_AREA_UNCATEGORIZED' ) ) {
+	define( 'WP_TEMPLATE_PART_AREA_UNCATEGORIZED', 'uncategorized' );
+}
+
 /**
  * Fixes the label of the 'wp_template_part' admin menu entry.
  */
@@ -118,3 +161,43 @@ function set_unique_slug_on_create_template_part( $post_id ) {
 	}
 }
 add_action( 'save_post_wp_template_part', 'set_unique_slug_on_create_template_part' );
+
+/**
+ * Returns a filtered list of allowed area types for template parts.
+ *
+ * @return array The supported template part area types.
+ */
+function gutenberg_get_allowed_template_part_area_types() {
+	$default_area_types = array(
+		WP_TEMPLATE_PART_AREA_HEADER,
+		WP_TEMPLATE_PART_AREA_FOOTER,
+		WP_TEMPLATE_PART_AREA_SIDEBAR,
+		WP_TEMPLATE_PART_AREA_UNCATEGORIZED,
+	);
+
+	/**
+	 * Filters the list of allowed template part area types.
+	 *
+	 * @param array $default_area_types An array of supported area types.
+	 */
+	return apply_filters( 'default_wp_template_part_area_types', $default_area_types );
+}
+
+/**
+ * Checks whether the input 'type' is a supported area type.
+ * Returns the input if supported, otherwise returns the 'other' type.
+ *
+ * @param string $type Template part area name.
+ *
+ * @return string Input if supported, else 'other'.
+ */
+function gutenberg_filter_template_part_area_type( $type ) {
+	if ( in_array( $type, gutenberg_get_allowed_template_part_area_types(), true ) ) {
+		return $type;
+	}
+	$warning_message  = '"' . $type . '"';
+	$warning_message .= __( ' is not a supported wp_template_part_area type and has been added as ', 'gutenberg' );
+	$warning_message .= '"' . WP_TEMPLATE_PART_AREA_UNCATEGORIZED . '".';
+	trigger_error( $warning_message, E_USER_NOTICE );
+	return WP_TEMPLATE_PART_AREA_UNCATEGORIZED;
+}