Framework: Support registering and invoking actions in the data module

data/README.md

@@ -39,6 +39,25 @@ Let's say the state of our plugin (registered with the key `myPlugin`) has the f
 wp.data.registerSelectors( 'myPlugin', { getTitle: ( state ) => state.title } );
 ```
 
+### `wp.data.registerActions( reducerKey: string, newActions: object )`
+
+If your module or plugin needs to expose its actions to other modules and plugins, you'll have to register action creators.
+
+An action creator is a function that takes arguments and returns an action object dispatch to the registered reducer to update the state.
+
+#### Example:
+
+```js
+wp.data.registerActions( 'myPlugin', {
+	setTitle( newTitle ) {
+		return {
+			type: 'SET_TITLE',
+			title: newTitle,
+		};
+	},
+} );
+```
+
 ### `wp.data.select( key: string )`
 
 This function allows calling any registered selector. Given a module's key, this function returns an object of all selector functions registered for the module.
@@ -49,18 +68,14 @@ This function allows calling any registered selector. Given a module's key, this
 wp.data.select( 'myPlugin' ).getTitle(); // Returns "My post title"
 ```
 
-### `wp.data.query( mapSelectorsToProps: function )( WrappedComponent: Component )`
+### `wp.data.dispatch( key: string )`
 
-If you use a React or WordPress Element, a Higher Order Component is made available to inject data into your components like so:
+This function allows calling any registered action. Given a module's key, this function returns an object of all action creators functions registered for the module.
 
-```js
-const Component = ( { title } ) => <div>{ title }</div>;
+#### Example:
 
-wp.data.query( select => {
-	return {
-		title: select( 'myPlugin' ).getTitle(),
-	};
-} )( Component );
+```js
+wp.data.dispatch( 'myPlugin' ).setTitle( 'new Title' ); // Dispatches the setTitle action to the reducer
 ```
 
 ### `wp.data.subscribe( listener: function )`
@@ -80,3 +95,38 @@ const unsubscribe = wp.data.subscribe( () => {
 // Unsubcribe.
 unsubscribe();
 ```
+
+### `wp.data.withSelect( mapStateToProps: Object|Function )( WrappedComponent: Component )`
+
+To inject state-derived props into a WordPress Element Component, use the `withSelect` higher-order component:
+
+```jsx
+const Component = ( { title } ) => <div>{ title }</div>;
+
+const EnhancedComponent = wp.data.withSelect( ( select ) => {
+	return {
+		title: select( 'myPlugin' ).getTitle,		
+	};
+} )( Component );
+```
+
+### `wp.data.withDispatch( propsToDispatchers: Object )( WrappedComponent: Component )`
+
+To manipulate store data, you can pass dispatching actions into your component as props using the `withDispatch` higher-order component:
+
+```jsx
+const Component = ( { title, updateTitle } ) => <input value={ title } onChange={ updateTitle } />;
+
+const EnhancedComponent = wp.element.compose( [
+	wp.data.withSelect( ( select ) => {
+		return {
+			title: select( 'myPlugin' ).getTitle(),
+		};
+	} ),
+	wp.data.withDispatch( ( dispatch ) => {
+		return {
+			updateTitle: dispatch( 'myPlugin' ).setTitle,			
+		};
+	} ),
+] )( Component );
+```

data/index.js

@@ -1,14 +1,15 @@
 /**
  * External dependencies
  */
-import { connect } from 'react-redux';
+import isEqualShallow from 'is-equal-shallow';
 import { createStore } from 'redux';
 import { flowRight, without, mapValues } from 'lodash';
 
 /**
  * WordPress dependencies
  */
 import { deprecated } from '@wordpress/utils';
+import { Component, getWrapperDisplayName } from '@wordpress/element';
 
 /**
  * Internal dependencies
@@ -20,6 +21,7 @@ export { loadAndPersist, withRehydratation } from './persist';
  */
 const stores = {};
 const selectors = {};
+const actions = {};
 let listeners = [];
 
 /**
@@ -29,21 +31,6 @@ export function globalListener() {
 	listeners.forEach( listener => listener() );
 }
 
-/**
- * Subscribe to changes to any data.
- *
- * @param {Function}   listener Listener function.
- *
- * @return {Function}           Unsubscribe function.
- */
-export const subscribe = ( listener ) => {
-	listeners.push( listener );
-
-	return () => {
-		listeners = without( listeners, listener );
-	};
-};
-
 /**
  * Registers a new sub-reducer to the global state and returns a Redux-like store object.
  *
@@ -79,6 +66,34 @@ export function registerSelectors( reducerKey, newSelectors ) {
 	selectors[ reducerKey ] = mapValues( newSelectors, createStateSelector );
 }
 
+/**
+ * Registers actions for external usage.
+ *
+ * @param {string} reducerKey   Part of the state shape to register the
+ *                              selectors for.
+ * @param {Object} newActions   Actions to register.
+ */
+export function registerActions( reducerKey, newActions ) {
+	const store = stores[ reducerKey ];
+	const createBoundAction = ( action ) => ( ...args ) => store.dispatch( action( ...args ) );
+	actions[ reducerKey ] = mapValues( newActions, createBoundAction );
+}
+
+/**
+ * Subscribe to changes to any data.
+ *
+ * @param {Function}   listener Listener function.
+ *
+ * @return {Function}           Unsubscribe function.
+ */
+export const subscribe = ( listener ) => {
+	listeners.push( listener );
+
+	return () => {
+		listeners = without( listeners, listener );
+	};
+};
+
 /**
  * Calls a selector given the current state and extra arguments.
  *
@@ -102,33 +117,142 @@ export function select( reducerKey ) {
 }
 
 /**
- * Higher Order Component used to inject data using the registered selectors.
+ * Returns the available actions for a part of the state.
  *
- * @param {Function} mapSelectorsToProps Gets called with the selectors object
- *                                       to determine the data for the
- *                                       component.
+ * @param {string} reducerKey Part of the state shape to dispatch the
+ *                            action for.
  *
- * @return {Function} Renders the wrapped component and passes it data.
+ * @return {*} The action's returned value.
  */
-export const query = ( mapSelectorsToProps ) => ( WrappedComponent ) => {
-	const store = {
-		getState() {
-			return mapValues( stores, subStore => subStore.getState() );
-		},
-		subscribe,
-		dispatch() {
-			// eslint-disable-next-line no-console
-			console.warn( 'Dispatch is not supported.' );
-		},
-	};
-	const connectWithStore = ( ...args ) => {
-		const ConnectedWrappedComponent = connect( ...args )( WrappedComponent );
-		return ( props ) => {
-			return <ConnectedWrappedComponent { ...props } store={ store } />;
-		};
-	};
+export function dispatch( reducerKey ) {
+	return actions[ reducerKey ];
+}
+
+/**
+ * Higher-order component used to inject state-derived props using registered
+ * selectors.
+ *
+ * @param {Function} mapStateToProps Function called on every state change,
+ *                                   expected to return object of props to
+ *                                   merge with the component's own props.
+ *
+ * @return {Component} Enhanced component with merged state data props.
+ */
+export const withSelect = ( mapStateToProps ) => ( WrappedComponent ) => {
+	class ComponentWithSelect extends Component {
+		constructor() {
+			super( ...arguments );
+
+			this.runSelection = this.runSelection.bind( this );
+
+			this.state = {};
+		}
+
+		componentWillMount() {
+			this.subscribe();
+
+			// Populate initial state.
+			this.runSelection();
+		}
+
+		componentWillReceiveProps( nextProps ) {
+			if ( ! isEqualShallow( nextProps, this.props ) ) {
+				this.runSelection( nextProps );
+			}
+		}
+
+		componentWillUnmount() {
+			this.unsubscribe();
+		}
+
+		subscribe() {
+			this.unsubscribe = subscribe( this.runSelection );
+		}
+
+		runSelection( props = this.props ) {
+			const newState = mapStateToProps( select, props );
+			if ( ! isEqualShallow( newState, this.state ) ) {
+				this.setState( newState );
+			}
+		}
+
+		render() {
+			return <WrappedComponent { ...this.props } { ...this.state } />;
+		}
+	}
+
+	ComponentWithSelect.displayName = getWrapperDisplayName( WrappedComponent, 'select' );
+
+	return ComponentWithSelect;
+};
+
+/**
+ * Higher-order component used to add dispatch props using registered action
+ * creators.
+ *
+ * @param {Object} mapDispatchToProps Object of prop names where value is a
+ *                                    dispatch-bound action creator, or a
+ *                                    function to be called with with the
+ *                                    component's props and returning an
+ *                                    action creator.
+ *
+ * @return {Component} Enhanced component with merged dispatcher props.
+ */
+export const withDispatch = ( mapDispatchToProps ) => ( WrappedComponent ) => {
+	class ComponentWithDispatch extends Component {
+		constructor() {
+			super( ...arguments );
+
+			this.proxyProps = {};
+		}
+
+		componentWillMount() {
+			this.setProxyProps( this.props );
+		}
+
+		componentWillUpdate( nextProps ) {
+			this.setProxyProps( nextProps );
+		}
+
+		proxyDispatch( propName, ...args ) {
+			// Original dispatcher is a pre-bound (dispatching) action creator.
+			mapDispatchToProps( dispatch, this.props )[ propName ]( ...args );
+		}
+
+		setProxyProps( props ) {
+			// Assign as instance property so that in reconciling subsequent
+			// renders, the assigned prop values are referentially equal.
+			const propsToDispatchers = mapDispatchToProps( dispatch, props );
+			this.proxyProps = mapValues( propsToDispatchers, ( dispatcher, propName ) => {
+				// Prebind with prop name so we have reference to the original
+				// dispatcher to invoke. Track between re-renders to avoid
+				// creating new function references every render.
+				if ( this.proxyProps.hasOwnProperty( propName ) ) {
+					return this.proxyProps[ propName ];
+				}
+
+				return this.proxyDispatch.bind( this, propName );
+			} );
+		}
+
+		render() {
+			return <WrappedComponent { ...this.props } { ...this.proxyProps } />;
+		}
+	}
+
+	ComponentWithDispatch.displayName = getWrapperDisplayName( WrappedComponent, 'dispatch' );
+
+	return ComponentWithDispatch;
+};
+
+export const query = ( mapSelectToProps ) => {
+	deprecated( 'wp.data.query', {
+		version: '2.5',
+		alternative: 'wp.data.withSelect',
+		plugin: 'Gutenberg',
+	} );
 
-	return connectWithStore( ( state, ownProps ) => {
-		return mapSelectorsToProps( select, ownProps );
+	return withSelect( ( props ) => {
+		return mapSelectToProps( select, props );
 	} );
 };