Add basic Redux infra based on ng-redux

Author: vojtechszocs

.eslintrc.json

@@ -22,6 +22,7 @@
     "sendDataWithRx": false,
     "vanillaJsAPI": false, // local: miq_api.js
     "ManageIQ": false, // local: mig_global.js
+    "miqApp": false, // alias: ManageIQ.angular.app
     "Promise": false, // bower: es6-shim
     "_": false, // bower: lodash
     "__": false, // local: i18n.js

app/assets/javascripts/application.js

@@ -14,6 +14,7 @@
 //= require angular-bootstrap/ui-bootstrap-tpls
 //= require angular-sanitize
 //= require angular.validators
+//= require ng-redux/dist/ng-redux
 //= require moment
 //= require moment-strftime/lib/moment-strftime
 //= require moment-timezone

app/assets/javascripts/miq_angular_application.js

@@ -6,6 +6,7 @@ ManageIQ.angular.app = angular.module('ManageIQ', [
   'patternfly.charts',
   'frapontillo.bootstrap-switch',
   'angular.validators',
+  'ngRedux',
   'miq.api',
   'miq.card',
   'miq.compat',

app/assets/javascripts/miq_global.js

@@ -84,5 +84,6 @@ if (! window.ManageIQ) {
       debounced: {}, // running debounces
       debounce_counter: 1,
     },
+    redux: null // Redux API
   };
 }

app/javascript/miq-redux/middleware.ts

@@ -0,0 +1,5 @@
+import { Middleware } from 'redux';
+
+export const middlewares: Middleware[] = [];
+
+// add middleware for handling async operations and side effects

app/javascript/miq-redux/reducer.ts

@@ -0,0 +1,74 @@
+import { Unsubscribe } from 'redux';
+
+import { AppState, AppReducer, Action, AppReducerHash } from './redux-typings';
+
+const reducers: Set<AppReducer> = new Set();
+
+/**
+ * Root reducer, used when creating the Redux store.
+ *
+ * The implementation simply invokes each registered `AppReducer`
+ * in a loop.
+ *
+ * @param state Current application state.
+ * @param action Action being dispatched.
+ *
+ * @returns New application state.
+ */
+export function rootReducer(state: AppState, action: Action): AppState {
+  let newState = state;
+
+  reducers.forEach((appReducer) => {
+    newState = appReducer(newState, action);
+  });
+
+  return newState;
+}
+
+/**
+ * Add given reducer to the list of registered application reducers.
+ *
+ * @param appReducer Reducer to add.
+ *
+ * @returns Function to remove (unsubscribe) the given reducer.
+ */
+export function addReducer(appReducer: AppReducer): Unsubscribe {
+  reducers.add(appReducer);
+
+  return () => {
+    reducers.delete(appReducer);
+  };
+}
+
+/**
+ * Remove all registered application reducers.
+ *
+ * *For testing purposes only.*
+ */
+export function clearReducers(): void {
+  reducers.clear();
+}
+
+/**
+ * Apply a collection of reducers, represented as `AppReducerHash`,
+ * to compute new application state.
+ *
+ * The implementation looks for a key that matches action's `type`.
+ * If present, the corresponding reducer is invoked to compute the
+ * new state. Otherwise, original state is returned.
+ *
+ * @param reducerHash Reducer hash to use.
+ * @param state Current application state.
+ * @param action Action being dispatched.
+ *
+ * @returns New application state.
+ */
+export function applyReducerHash(reducerHash: AppReducerHash, state: AppState, action: Action): AppState {
+  let newState = state;
+
+  if (reducerHash.hasOwnProperty(action.type)) {
+    newState = reducerHash[action.type](state, action);
+  }
+
+  return newState;
+}

app/javascript/miq-redux/redux-typings.ts

@@ -0,0 +1,53 @@
+import { Reducer, Action as BaseAction, Store, Unsubscribe } from 'redux';
+
+/**
+ * Application state.
+ *
+ * Its shape depends on specific `AppReducer` functions added through
+ * `ReduxApi`. Therefore, its shape is dynamic and declared simply as
+ * `object`.
+ */
+export type AppState = object;
+
+/**
+ * Application reducer, operating on `AppState`.
+ *
+ * As per Redux design, reducers should
+ * - be pure functions without side effects,
+ * - return new state if `action` was acted upon, otherwise return
+ *   original state.
+ */
+export type AppReducer = Reducer<AppState>;
+
+/**
+ * Redux action object.
+ *
+ * As per Redux design, each action must define the `type` property.
+ * Any data associated with the action should go into the `payload`.
+ */
+export interface Action extends BaseAction {
+  payload?: any;
+}
+
+/**
+ * Application reducer hash, containing action types as keys and the
+ * corresponding reducers (to handle those action types) as values.
+ */
+export interface AppReducerHash {
+  [propName: string]: AppReducer;
+}
+
+/**
+ * Redux store, holding application's state tree and providing
+ * functions to dispatch actions and subscribe to state changes.
+ */
+export type ReduxStore = Store<AppState>;
+
+/**
+ * `ManageIQ.redux` API.
+ */
+export interface ReduxApi {
+  store: ReduxStore;
+  addReducer(appReducer: AppReducer): Unsubscribe;
+  applyReducerHash(reducerHash: AppReducerHash, state: AppState, action: Action): AppState;
+}

app/javascript/miq-redux/store.ts

@@ -0,0 +1,29 @@
+import { IModule } from 'angular';
+import { devToolsEnhancer, EnhancerOptions } from 'redux-devtools-extension/logOnlyInProduction';
+
+import { rootReducer } from './reducer';
+import { middlewares } from './middleware';
+import { AppState } from './redux-typings';
+
+const devToolsOptions: EnhancerOptions = {};
+
+/**
+ * Configure Angular application to use Redux store using `ng-redux`
+ * implementation.
+ *
+ * The store supports Redux DevTools browser extension in development
+ * as well as production, allowing users to inspect application state.
+ * In production, however, Redux DevTools runs in *log only* mode.
+ *
+ * @param app Angular application to configure.
+ * @param initialState Initial application state.
+ */
+export function configureNgReduxStore(app: IModule, initialState: AppState): void {
+  app.config(['$ngReduxProvider', ($ngReduxProvider) => {
+    $ngReduxProvider.createStoreWith(
+      rootReducer,
+      middlewares,
+      [devToolsEnhancer(devToolsOptions)],
+      initialState);
+  }]);
+}

app/javascript/miq-redux/test-helper.ts

@@ -0,0 +1,13 @@
+import { IModule } from 'angular';
+
+import { rootReducer, addReducer, clearReducers, applyReducerHash } from './reducer';
+
+const app: IModule = miqApp;
+
+// allow unit-testing specific module exports
+if (jasmine) {
+  app.constant('_rootReducer', rootReducer);
+  app.constant('_addReducer', addReducer);
+  app.constant('_clearReducers', clearReducers);
+  app.constant('_applyReducerHash', applyReducerHash);
+}

app/javascript/packs/custom-typings.ts

@@ -0,0 +1,14 @@
+/**
+ * Runtime global, contains all application-specific objects.
+ */
+declare const ManageIQ: any;
+
+/**
+ * Compile-time global, alias for `ManageIQ.angular.app`.
+ */
+declare const miqApp: any;
+
+/**
+ * Runtime global, available when running tests with Jasmine.
+ */
+declare const jasmine: any;