Permit unbounded per_page=-1 requests for Categories and Tags

core-data/resolvers.js

@@ -21,7 +21,7 @@ import { getEntity } from './entities';
  */
 export async function* getCategories() {
 	yield setRequested( 'terms', 'categories' );
-	const categories = await apiRequest( { path: '/wp/v2/categories' } );
+	const categories = await apiRequest( { path: '/wp/v2/categories?per_page=-1' } );
 	yield receiveTerms( 'categories', categories );
 }
 

editor/components/post-taxonomies/flat-term-selector.js

@@ -16,7 +16,7 @@ import { withSelect, withDispatch } from '@wordpress/data';
  * Module constants
  */
 const DEFAULT_QUERY = {
-	per_page: 100,
+	per_page: -1,
 	orderby: 'count',
 	order: 'desc',
 	_fields: 'id,name',

editor/components/post-taxonomies/hierarchical-term-selector.js

@@ -17,7 +17,7 @@ import { withSelect, withDispatch } from '@wordpress/data';
  * Module Constants
  */
 const DEFAULT_QUERY = {
-	per_page: 100,
+	per_page: -1,
 	orderby: 'count',
 	order: 'desc',
 	_fields: 'id,name,parent',

lib/rest-api.php

@@ -353,6 +353,17 @@ function gutenberg_register_post_prepare_functions( $post_type ) {
 }
 add_filter( 'registered_post_type', 'gutenberg_register_post_prepare_functions' );
 
+/**
+ * Whenever a taxonomy is registered, ensure we're hooked into its WP REST API response.
+ *
+ * @param string $taxonomy The newly registered taxonomy.
+ */
+function gutenberg_register_taxonomy_prepare_functions( $taxonomy ) {
+	add_filter( "rest_{$taxonomy}_collection_params", 'gutenberg_filter_term_collection_parameters', 10, 2 );
+	add_filter( "rest_{$taxonomy}_query", 'gutenberg_filter_term_query_arguments', 10, 2 );
+}
+add_filter( 'registered_taxonomy', 'gutenberg_register_taxonomy_prepare_functions' );
+
 /**
  * Includes the value for the 'viewable' attribute of a post type resource.
  *
@@ -465,6 +476,8 @@ function gutenberg_ensure_wp_json_has_theme_supports( $response ) {
 function gutenberg_handle_early_callback_checks( $response, $handler, $request ) {
 	$routes = array(
 		'/wp/v2/blocks',
+		'/wp/v2/categories',
+		'/wp/v2/tags',
 		'/wp/v2/pages',
 		'/wp/v2/users',
 	);
@@ -538,6 +551,51 @@ function gutenberg_filter_post_query_arguments( $prepared_args, $request ) {
 	return $prepared_args;
 }
 
+/**
+ * Include additional query parameters on the terms query endpoint.
+ *
+ * @see https://core.trac.wordpress.org/ticket/43998
+ *
+ * @param array  $query_params JSON Schema-formatted collection parameters.
+ * @param object $taxonomy     Taxonomy being accessed.
+ * @return array
+ */
+function gutenberg_filter_term_collection_parameters( $query_params, $taxonomy ) {
+	$taxonomies = array( 'category', 'post_tag' );
+	if ( in_array( $taxonomy->name, $taxonomies, true )
+		&& isset( $query_params['per_page'] ) ) {
+		// Change from '1' to '-1', which means unlimited.
+		$query_params['per_page']['minimum'] = -1;
+		// Default sanitize callback is 'absint', which won't work in our case.
+		$query_params['per_page']['sanitize_callback'] = 'rest_sanitize_request_arg';
+	}
+	return $query_params;
+}
+
+/**
+ * Filter term collection query parameters to include specific behavior.
+ *
+ * @see https://core.trac.wordpress.org/ticket/43998
+ *
+ * @param array           $prepared_args Array of arguments for WP_Term_Query.
+ * @param WP_REST_Request $request       The current request.
+ * @return array
+ */
+function gutenberg_filter_term_query_arguments( $prepared_args, $request ) {
+	// Can't check the actual taxonomy here because it's not
+	// passed through in $prepared_args (or the filter generally).
+	if ( 0 === strpos( $request->get_route(), '/wp/v2/' ) ) {
+		if ( -1 === $prepared_args['number'] ) {
+			// This should be unset( $prepared_args['number'] )
+			// but WP_REST_Terms Controller needs to be updated to support
+			// unbounded queries.
+			// Will be addressed in https://core.trac.wordpress.org/ticket/43998.
+			$prepared_args['number'] = 100000;
+		}
+	}
+	return $prepared_args;
+}
+
 /**
  * Include additional query parameters on the user query endpoint.
  *

phpunit/class-gutenberg-rest-api-test.php

@@ -280,6 +280,26 @@ public function test_get_items_unbounded_per_page_unauthorized() {
 		$this->assertEquals( 'rest_forbidden_per_page', $data['code'] );
 	}
 
+	public function test_get_categories_unbounded_per_page() {
+		wp_set_current_user( $this->author );
+		$this->factory->category->create();
+		$request = new WP_REST_Request( 'GET', '/wp/v2/categories' );
+		$request->set_param( 'per_page', '-1' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertEquals( 200, $response->get_status() );
+	}
+
+	public function test_get_categories_unbounded_per_page_unauthorized() {
+		wp_set_current_user( $this->subscriber );
+		$this->factory->category->create();
+		$request = new WP_REST_Request( 'GET', '/wp/v2/categories' );
+		$request->set_param( 'per_page', '-1' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertEquals( 403, $response->get_status() );
+		$data = $response->get_data();
+		$this->assertEquals( 'rest_forbidden_per_page', $data['code'] );
+	}
+
 	public function test_get_pages_unbounded_per_page() {
 		wp_set_current_user( $this->author );
 		$this->factory->post->create( array( 'post_type' => 'page' ) );