REST API: Terms: Respect taxonomy's default query args.

It is possible to supply a set of default query `args` to `register_taxonomy()` which will be used when querying a list of terms -- for example, `orderby` in order to specify how the resulting list of terms should be sorted.

The Terms REST API controller previously respected these default query args only if the request included a post ID. This changeset makes it so that the default args will also be respected if no post ID is provided.

Props bernhard-reiter, jsnajdr.
Fixes #62500.

git-svn-id: https://develop.svn.wordpress.org/trunk@59458 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php

@@ -227,6 +227,7 @@ public function get_items_permissions_check( $request ) {
 	 * Retrieves terms associated with a taxonomy.
 	 *
 	 * @since 4.7.0
+	 * @since 6.8.0 Respect default query arguments set for the taxonomy upon registration.
 	 *
 	 * @param WP_REST_Request $request Full details about the request.
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
@@ -295,6 +296,22 @@ public function get_items( $request ) {
 			}
 		}
 
+		/*
+		 * When a taxonomy is registered with an 'args' array,
+		 * those params override the `$args` passed to this function.
+		 *
+		 * We only need to do this if no `post` argument is provided.
+		 * Otherwise, terms will be fetched using `wp_get_object_terms()`,
+		 * which respects the default query arguments set for the taxonomy.
+		 */
+		if (
+			empty( $prepared_args['post'] ) &&
+			isset( $taxonomy_obj->args ) &&
+			is_array( $taxonomy_obj->args )
+		) {
+			$prepared_args = array_merge( $prepared_args, $taxonomy_obj->args );
+		}
+
 		/**
 		 * Filters get_terms() arguments when querying terms via the REST API.
 		 *

tests/phpunit/tests/rest-api/rest-tags-controller.php

@@ -482,6 +482,55 @@ public function test_get_items_custom_tax_post_args() {
 		$this->assertSame( 'Cape', $data[0]['name'] );
 	}
 
+	/**
+	 * @ticket 62500
+	 */
+	public function test_get_items_custom_tax_without_post_arg_respects_tax_query_args() {
+		register_taxonomy(
+			'batman',
+			'post',
+			array(
+				'show_in_rest' => true,
+				'sort'         => true,
+				'args'         => array(
+					'order'   => 'DESC',
+					'orderby' => 'name',
+				),
+			)
+		);
+		$controller = new WP_REST_Terms_Controller( 'batman' );
+		$controller->register_routes();
+		$term1 = self::factory()->term->create(
+			array(
+				'name'     => 'Cycle',
+				'taxonomy' => 'batman',
+			)
+		);
+		$term2 = self::factory()->term->create(
+			array(
+				'name'     => 'Pod',
+				'taxonomy' => 'batman',
+			)
+		);
+		$term3 = self::factory()->term->create(
+			array(
+				'name'     => 'Cave',
+				'taxonomy' => 'batman',
+			)
+		);
+
+		$request  = new WP_REST_Request( 'GET', '/wp/v2/batman' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertSame( 200, $response->get_status() );
+
+		$data = $response->get_data();
+		$this->assertCount( 3, $data );
+		$this->assertSame(
+			array( 'Pod', 'Cycle', 'Cave' ),
+			array_column( $data, 'name' )
+		);
+	}
+
 	public function test_get_items_search_args() {
 		$tag1 = self::factory()->tag->create( array( 'name' => 'Apple' ) );
 		$tag2 = self::factory()->tag->create( array( 'name' => 'Banana' ) );