Add support for filtering products by featured status

- Added `featured` attribute to `ProductCollectionQuery` type to enable filtering by featured status.
- Implemented `FeaturedProductsControl` to provide a toggle option in the inspector controls.
- Integrated `FeaturedProductsControl` into `ProductCollectionInspectorControls`.
- Added `get_featured_query` function in `ProductCollection` class to generate query for fetching featured products.
- Updated existing functions and queries in `ProductCollection` class to support featured products filtering.

assets/js/blocks/product-collection/constants.ts

@@ -45,6 +45,7 @@ export const DEFAULT_QUERY: ProductCollectionQuery = {
 	inherit: null,
 	taxQuery: {},
 	isProductCollectionBlock: true,
+	featured: false,
 	woocommerceOnSale: false,
 	woocommerceStockStatus: getDefaultStockStatuses(),
 	woocommerceAttributes: [],
@@ -86,4 +87,5 @@ export const DEFAULT_FILTERS: Partial< ProductCollectionQuery > = {
 	woocommerceAttributes: [],
 	taxQuery: DEFAULT_QUERY.taxQuery,
 	woocommerceHandPickedProducts: [],
+	featured: DEFAULT_QUERY.featured,
 };

assets/js/blocks/product-collection/inspector-controls/featured-products-control.tsx

@@ -0,0 +1,52 @@
+/**
+ * External dependencies
+ */
+import { __ } from '@wordpress/i18n';
+import {
+	BaseControl,
+	ToggleControl,
+	// @ts-expect-error Using experimental features
+	// eslint-disable-next-line @wordpress/no-unsafe-wp-apis
+	__experimentalToolsPanelItem as ToolsPanelItem,
+} from '@wordpress/components';
+
+/**
+ * Internal dependencies
+ */
+import { QueryControlProps } from '../types';
+
+const FeaturedProductsControl = ( props: QueryControlProps ) => {
+	const { query, setQueryAttribute } = props;
+
+	return (
+		<ToolsPanelItem
+			label={ __( 'Featured', 'woo-gutenberg-products-block' ) }
+			hasValue={ () => query.featured === true }
+			onDeselect={ () => {
+				setQueryAttribute( {
+					featured: false,
+				} );
+			} }
+		>
+			<BaseControl
+				id="product-collection-featured-products-control"
+				label={ __( 'Featured', 'woo-gutenberg-products-block' ) }
+			>
+				<ToggleControl
+					label={ __(
+						'Show only featured products',
+						'woo-gutenberg-products-block'
+					) }
+					checked={ query.featured || false }
+					onChange={ ( featured ) => {
+						setQueryAttribute( {
+							featured,
+						} );
+					} }
+				/>
+			</BaseControl>
+		</ToolsPanelItem>
+	);
+};
+
+export default FeaturedProductsControl;

assets/js/blocks/product-collection/inspector-controls/index.tsx

@@ -39,6 +39,7 @@ import AttributesControl from './attributes-control';
 import TaxonomyControls from './taxonomy-controls';
 import HandPickedProductsControl from './hand-picked-products-control';
 import LayoutOptionsControl from './layout-options-control';
+import FeaturedProductsControl from './featured-products-control';
 
 const ProductCollectionInspectorControls = (
 	props: BlockEditProps< ProductCollectionAttributes >
@@ -98,6 +99,7 @@ const ProductCollectionInspectorControls = (
 					<KeywordControl { ...queryControlProps } />
 					<AttributesControl { ...queryControlProps } />
 					<TaxonomyControls { ...queryControlProps } />
+					<FeaturedProductsControl { ...queryControlProps } />
 				</ToolsPanel>
 			) : null }
 			<ProductCollectionFeedbackPrompt />

assets/js/blocks/product-collection/types.ts

@@ -39,6 +39,10 @@ export interface ProductCollectionQuery {
 	postType: string;
 	search: string;
 	taxQuery: Record< string, number[] >;
+	/**
+	 * If true, show only featured products.
+	 */
+	featured: boolean;
 	woocommerceOnSale: boolean;
 	/**
 	 * Filter products by their stock status.

src/BlockTypes/ProductCollection.php

@@ -207,6 +207,8 @@ public function update_rest_query_in_editor( $args, $request ): array {
 		$stock_status        = $request->get_param( 'woocommerceStockStatus' );
 		$product_attributes  = $request->get_param( 'woocommerceAttributes' );
 		$handpicked_products = $request->get_param( 'woocommerceHandPickedProducts' );
+		$featured            = $request->get_param( 'featured' ) === 'true';
+
 		// This argument is required for the tests to PHP Unit Tests to run correctly.
 		// Most likely this argument is being accessed in the test environment image.
 		$args['author'] = '';
@@ -219,6 +221,7 @@ public function update_rest_query_in_editor( $args, $request ): array {
 				'stock_status'        => $stock_status,
 				'product_attributes'  => $product_attributes,
 				'handpicked_products' => $handpicked_products,
+				'featured'            => $featured,
 			)
 		);
 	}
@@ -305,6 +308,7 @@ private function get_final_frontend_query( $query, $page = 1, $is_exclude_applie
 		$product_attributes  = $query['woocommerceAttributes'] ?? [];
 		$taxonomies_query    = $this->get_filter_by_taxonomies_query( $query['tax_query'] ?? [] );
 		$handpicked_products = $query['woocommerceHandPickedProducts'] ?? [];
+		$featured            = $query['featured'] ?? false;
 
 		$final_query = $this->get_final_query_args(
 			$common_query_values,
@@ -315,6 +319,7 @@ private function get_final_frontend_query( $query, $page = 1, $is_exclude_applie
 				'product_attributes'  => $product_attributes,
 				'taxonomies_query'    => $taxonomies_query,
 				'handpicked_products' => $handpicked_products,
+				'featured'            => $featured,
 			),
 			$is_exclude_applied_filters
 		);
@@ -335,10 +340,11 @@ private function get_final_query_args( $common_query_values, $query, $is_exclude
 		$on_sale_query       = $this->get_on_sale_products_query( $query['on_sale'] );
 		$stock_query         = $this->get_stock_status_query( $query['stock_status'] );
 		$visibility_query    = is_array( $query['stock_status'] ) ? $this->get_product_visibility_query( $stock_query ) : [];
+		$featured            = $query['featured'] ?? false;
+		$featured_query      = $this->get_featured_query( $featured );
 		$attributes_query    = $this->get_product_attributes_query( $query['product_attributes'] );
 		$taxonomies_query    = $query['taxonomies_query'] ?? [];
-		$tax_query           = $this->merge_tax_queries( $visibility_query, $attributes_query, $taxonomies_query );
-
+		$tax_query           = $this->merge_tax_queries( $visibility_query, $attributes_query, $taxonomies_query, $featured_query );
 		// We exclude applied filters to generate product ids for the filter blocks.
 		$applied_filters_query = $is_exclude_applied_filters ? [] : $this->get_queries_by_applied_filters();
 
@@ -628,6 +634,35 @@ private function get_product_visibility_query( $stock_query ) {
 		);
 	}
 
+	/**
+	 * Generates a tax query to filter products based on their "featured" status.
+	 * If the `$featured` parameter is true, the function will return a tax query
+	 * that filters products to only those marked as featured.
+	 * If `$featured` is false, an empty array is returned, meaning no filtering will be applied.
+	 *
+	 * @param bool $featured A flag indicating whether to filter products based on featured status.
+	 *
+	 * @return array A tax query for fetching featured products if `$featured` is true; otherwise, an empty array.
+	 */
+	private function get_featured_query( $featured ) {
+		if ( ! $featured ) {
+			return array();
+		}
+
+		return array(
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_tax_query
+			'tax_query' => array(
+				array(
+					'taxonomy' => 'product_visibility',
+					'field'    => 'name',
+					'terms'    => 'featured',
+					'operator' => 'IN',
+				),
+			),
+		);
+	}
+
+
 	/**
 	 * Merge tax_queries from various queries.
 	 *