add crude support for a callback for when middleware is applied, allo…

…wing support for redux-saga

src/client.js

@@ -6,14 +6,18 @@ import { render as renderDevtools } from './client/devtools';
 
 // dependencies of external source. these resolve via webpack aliases
 // as assigned in merge-configs.js
-import middleware from 'universal-redux/middleware';
+import middleware, { middlewareAppliedCallback } from 'universal-redux/middleware';
 import createRootClientComponent from 'universal-redux/rootClientComponent';
 
 const dest = document.getElementById('content');
 
 const store = createStore(middleware, window.__data);
 const devComponent = renderDevtools();
 
+if (middlewareAppliedCallback) {
+  middlewareAppliedCallback();
+}
+
 // There is probably no need to be asynchronous here
 createRootClientComponent(store, __PROVIDERS__, devComponent)
   .then((root) => {

src/server/renderer.js

@@ -31,6 +31,13 @@ export default (projectConfig, projectToolsConfig) => {
     const store = createStore(middleware);
     const routes = getRoutes(store);
 
+    if (config.redux.middleware) {
+      const callback = require(path.resolve(config.redux.middleware)).middlewareAppliedCallback;
+      if (callback) {
+        callback();
+      }
+    }
+
     if (__DISABLE_SSR__) {
       const content = html(config, tools.assets(), store, headers);
       return new Promise(resolve => send(200, content, resolve)).then(() => {