allow manual initialization and config as an arg

src/actions/config.js

@@ -1,11 +1,13 @@
 import yaml from "js-yaml";
-import { set, defaultsDeep, get } from "lodash";
+import Immutable from "immutable";
+import { set, defaultsDeep, get, flow } from "lodash";
 import { authenticateUser } from "Actions/auth";
 import * as publishModes from "Constants/publishModes";
 
 export const CONFIG_REQUEST = "CONFIG_REQUEST";
 export const CONFIG_SUCCESS = "CONFIG_SUCCESS";
 export const CONFIG_FAILURE = "CONFIG_FAILURE";
+export const CONFIG_MERGE = "CONFIG_MERGE";
 
 const defaults = {
   publish_mode: publishModes.SIMPLE,
@@ -82,21 +84,35 @@ export function configDidLoad(config) {
   };
 }
 
+export function mergeConfig(config) {
+  return { type: CONFIG_MERGE, payload: config };
+}
+
 export function loadConfig() {
   if (window.CMS_CONFIG) {
     return configDidLoad(window.CMS_CONFIG);
   }
-  return (dispatch) => {
+  return (dispatch, getState) => {
     dispatch(configLoading());
+    const config = getState().config;
 
     fetch("config.yml", { credentials: 'same-origin' })
     .then((response) => {
-      if (response.status !== 200) {
+      if (!config && response.status !== 200) {
         throw new Error(`Failed to load config.yml (${ response.status })`);
+      } else if (response.status !== 200) {
+        return '';
       }
       return response.text();
     })
     .then(parseConfig)
+    .then(resp => {
+      /**
+       * Merge any existing configuration using `Immutable.mergeDeep` for
+       * consistency with reducers.
+       */
+      return config ? config.mergeDeep(Immutable.fromJS(resp)).toJS() : config;
+    })
     .then(validateConfig)
     .then(applyDefaults)
     .then((config) => {

src/bootstrap.js

@@ -0,0 +1,67 @@
+import React from 'react';
+import { render } from 'react-dom';
+import { Provider } from 'react-redux';
+import { Route } from 'react-router-dom';
+import { ConnectedRouter } from 'react-router-redux';
+import history from 'Routing/history';
+import configureStore from 'Redux/configureStore';
+import { mergeConfig } from 'Actions/config';
+import { setStore } from 'ValueObjects/AssetProxy';
+import { ErrorBoundary } from 'UI'
+import App from 'App/App';
+import 'EditorWidgets';
+import 'MarkdownPlugins';
+import './index.css';
+
+function bootstrap({ config }) {
+  /**
+   * Log the version number.
+   */
+  console.log(`Netlify CMS version ${NETLIFY_CMS_VERSION}`);
+
+  /**
+   * Create mount element dynamically.
+   */
+  const el = document.createElement('div');
+  el.id = 'nc-root';
+  document.body.appendChild(el);
+
+  /**
+   * Configure Redux store.
+   */
+  const store = configureStore();
+
+  /**
+   * Dispatch config to store if received. This config will be merged into
+   * config.yml if it exists, and any portion that produces a conflict will be
+   * overwritten.
+   */
+  if (config) {
+    store.dispatch(mergeConfig(config));
+  }
+
+  /**
+   * Pass initial state into AssetProxy factory.
+   */
+  setStore(store);
+
+  /**
+   * Create connected root component.
+   */
+  const Root = () => (
+    <ErrorBoundary>
+      <Provider store={store}>
+        <ConnectedRouter history={history}>
+          <Route component={App}/>
+        </ConnectedRouter>
+      </Provider>
+    </ErrorBoundary>
+  );
+
+  /**
+   * Render application root.
+   */
+  render(<Root />, el);
+}
+
+export default bootstrap;

src/components/App/App.js

@@ -105,7 +105,6 @@ class App extends React.Component {
       openMediaLibrary,
     } = this.props;
 
-
     if (config === null) {
       return null;
     }
@@ -114,7 +113,7 @@ class App extends React.Component {
       return App.configError(config);
     }
 
-    if (config.get('isFetching')) {
+    if (config.get('isFetching') || !config.get('isLoaded')) {
       return <Loader active>Loading configuration...</Loader>;
     }
 

src/index.js

@@ -1,54 +1,16 @@
-import React from 'react';
-import createReactClass from 'create-react-class';
-import { render } from 'react-dom';
-import { Provider } from 'react-redux';
-import { Route } from 'react-router-dom';
-import { ConnectedRouter } from 'react-router-redux';
-import history from 'Routing/history';
-import configureStore from 'Redux/configureStore';
-import { setStore } from 'ValueObjects/AssetProxy';
-import { ErrorBoundary } from 'UI'
-import registry from 'Lib/registry';
-import App from 'App/App';
-import 'EditorWidgets';
-import 'MarkdownPlugins';
-import './index.css';
-
-/**
- * Log the version number.
- */
-console.log(`Netlify CMS version ${NETLIFY_CMS_VERSION}`);
-
-/**
- * Create mount element dynamically.
- */
-const el = document.createElement('div');
-el.id = 'nc-root';
-document.body.appendChild(el);
-
-/**
- * Configure Redux store.
- */
-const store = configureStore();
-setStore(store);
-
 /**
- * Create connected root component.
+ * This module provides a self-initializing CMS instance with API hooks added to
+ * the `window` object.
  */
-const Root = () => (
-  <ErrorBoundary>
-    <Provider store={store}>
-      <ConnectedRouter history={history}>
-        <Route component={App}/>
-      </ConnectedRouter>
-    </Provider>
-  </ErrorBoundary>
-);
+import React from 'react';
+import bootstrap from './bootstrap';
+import registry from 'Lib/registry';
+import createReactClass from 'create-react-class';
 
 /**
- * Render application root.
+ * Load the app.
  */
-render(<Root />, el);
+bootstrap();
 
 /**
  * Add extension hooks to global scope.

src/init.js

@@ -0,0 +1,7 @@
+/**
+ * This module provides manual initialization and registry hooks.
+ */
+import bootstrap from './bootstrap';
+import registry from 'Lib/registry';
+
+export { bootstrap as init, registry };

src/reducers/config.js

@@ -1,12 +1,21 @@
 import Immutable from 'immutable';
-import { CONFIG_REQUEST, CONFIG_SUCCESS, CONFIG_FAILURE } from 'Actions/config';
+import { CONFIG_REQUEST, CONFIG_SUCCESS, CONFIG_FAILURE, CONFIG_MERGE } from 'Actions/config';
 
 const config = (state = null, action) => {
   switch (action.type) {
+    case CONFIG_MERGE: {
+      const newConfig = Immutable.fromJS(action.payload);
+      return state ? state.mergeDeep(newConfig) : newConfig;
+    }
     case CONFIG_REQUEST:
+      if (state) {
+        return state.set('isFetching', true);
+      }
       return Immutable.Map({ isFetching: true });
     case CONFIG_SUCCESS:
-      return Immutable.fromJS(action.payload);
+      return Immutable.fromJS(action.payload).withMutations(map => {
+        map.set('isFetching', false).set('isLoaded', true);
+      });
     case CONFIG_FAILURE:
       return Immutable.Map({ error: action.payload.toString() });
     default:

webpack.dev.js

@@ -13,6 +13,7 @@ module.exports = merge.smart(require('./webpack.base.js'), {
       `webpack-dev-server/client?http://${ HOST }:${ PORT }/`,
       './index',
     ],
+    init: './init',
   },
   output: {
     path: path.join(__dirname, 'dist'),

webpack.prod.js

@@ -8,6 +8,7 @@ const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
 module.exports = merge.smart(require('./webpack.base.js'), {
   entry: {
     cms: './index',
+    init: './init',
   },
   output: {
     path: path.join(__dirname, 'dist'),