Introduce the concept of registry selectors

packages/core-data/src/selectors.js

@@ -7,7 +7,7 @@ import { map, find, get, filter, compact, defaultTo } from 'lodash';
 /**
  * WordPress dependencies
  */
-import { select } from '@wordpress/data';
+import { createRegistrySelector } from '@wordpress/data';
 import deprecated from '@wordpress/deprecated';
 
 /**
@@ -16,19 +16,6 @@ import deprecated from '@wordpress/deprecated';
 import { REDUCER_KEY } from './name';
 import { getQueriedItems } from './queried-data';
 
-/**
- * Returns true if resolution is in progress for the core selector of the given
- * name and arguments.
- *
- * @param {string} selectorName Core data selector name.
- * @param {...*}   args         Arguments passed to selector.
- *
- * @return {boolean} Whether resolution is in progress.
- */
-function isResolving( selectorName, ...args ) {
-	return select( 'core/data' ).isResolving( REDUCER_KEY, selectorName, args );
-}
-
 /**
  * Returns true if a request is in progress for embed preview data, or false
  * otherwise.
@@ -38,9 +25,9 @@ function isResolving( selectorName, ...args ) {
  *
  * @return {boolean} Whether a request is in progress for an embed preview.
  */
-export function isRequestingEmbedPreview( state, url ) {
-	return isResolving( 'getEmbedPreview', url );
-}
+export const isRequestingEmbedPreview = createRegistrySelector( ( registry ) => ( state, url ) => {
+	return registry.select( 'core/data' ).isResolving( REDUCER_KEY, 'getEmbedPreview', [ url ] );
+} );
 
 /**
  * Returns all available authors.

packages/data/src/factory.js

@@ -0,0 +1,12 @@
+/**
+ * Mark a function as a registry selector.
+ *
+ * @param {function} registrySelector Function receiving a registry object and returning a state selector.
+ *
+ * @return {function} marked registry selector.
+ */
+export function createRegistrySelector( registrySelector ) {
+	registrySelector.isRegistrySelector = true;
+
+	return registrySelector;
+}

packages/data/src/index.js

@@ -15,6 +15,7 @@ export { default as RegistryProvider, RegistryConsumer } from './components/regi
 export { default as __experimentalAsyncModeProvider } from './components/async-mode-provider';
 export { createRegistry } from './registry';
 export { plugins };
+export { createRegistrySelector } from './factory';
 
 /**
  * The combineReducers helper function turns an object whose values are different

packages/data/src/namespace-store.js

@@ -19,7 +19,7 @@ import createResolversCacheMiddleware from './resolvers-cache-middleware';
  *
  * @param {string} key              Identifying string used for namespace and redex dev tools.
  * @param {Object} options          Contains reducer, actions, selectors, and resolvers.
- * @param {Object} registry         Temporary registry reference, required for namespace updates.
+ * @param {Object} registry         registry reference.
  *
  * @return {Object} Store Object.
  */
@@ -32,7 +32,7 @@ export default function createNamespace( key, options, registry ) {
 		actions = mapActions( options.actions, store );
 	}
 	if ( options.selectors ) {
-		selectors = mapSelectors( options.selectors, store );
+		selectors = mapSelectors( options.selectors, store, registry );
 	}
 	if ( options.resolvers ) {
 		const fulfillment = getCoreDataFulfillment( registry, key );
@@ -100,10 +100,14 @@ function createReduxStore( reducer, key, registry ) {
  *                            public facing API. Selectors will get passed the
  *                            state as first argument.
  * @param {Object} store      The redux store to which the selectors should be mapped.
+ * @param {Object} registry         registry reference.
+ *
  * @return {Object}           Selectors mapped to the redux store provided.
  */
-function mapSelectors( selectors, store ) {
-	const createStateSelector = ( selector ) => function runSelector() {
+function mapSelectors( selectors, store, registry ) {
+	const createStateSelector = ( registeredSelector ) => function runSelector() {
+		const selector = registeredSelector.isRegistrySelector ? registeredSelector( registry ) : registeredSelector;
+
 		// This function is an optimized implementation of:
 		//
 		//   selector( store.getState(), ...arguments )

packages/data/src/test/registry.js

@@ -7,6 +7,7 @@ import { castArray, mapValues } from 'lodash';
  * Internal dependencies
  */
 import { createRegistry } from '../registry';
+import { createRegistrySelector } from '../factory';
 
 describe( 'createRegistry', () => {
 	let registry;
@@ -441,6 +442,27 @@ describe( 'createRegistry', () => {
 			expect( registry.select( 'reducer1' ).selector2() ).toEqual( 'result2' );
 			expect( selector2 ).toBeCalledWith( store.getState() );
 		} );
+
+		it( 'should run the registry selectors properly', () => {
+			const selector1 = () => 'result1';
+			const selector2 = createRegistrySelector( ( reg ) => () =>
+				reg.select( 'reducer1' ).selector1()
+			);
+			registry.registerStore( 'reducer1', {
+				reducer: () => 'state1',
+				selectors: {
+					selector1,
+				},
+			} );
+			registry.registerStore( 'reducer2', {
+				reducer: () => 'state1',
+				selectors: {
+					selector2,
+				},
+			} );
+
+			expect( registry.select( 'reducer2' ).selector2() ).toEqual( 'result1' );
+		} );
 	} );
 
 	describe( 'subscribe', () => {