Merge pull request #72 from bluedaniel/master

waitUntilValid function using ready function

Author: sokra

README.md

@@ -66,3 +66,40 @@ app.use(webpackMiddleware(webpack({
 	// options for formating the statistics
 }));
 ```
+
+## Advanced API
+
+This part shows how you might interact with the middleware during runtime:
+
+* `close(callback)` - stop watching for file changes
+	```js
+	var webpackDevMiddlewareInstance = webpackMiddleware(/* see example usage */);
+	app.use(webpackDevMiddlewareInstance);
+	// After 10 seconds stop watching for file changes:
+	setTimeout(function(){
+	  webpackDevMiddlewareInstance.close();
+	}, 10000);
+	```
+
+* `invalidate()` - recompile the bundle - e.g. after you changed the configuration
+	```js
+	var compiler = webpack(/* see example usage */);
+	var webpackDevMiddlewareInstance = webpackMiddleware(compiler);
+	app.use(webpackDevMiddlewareInstance);
+	setTimeout(function(){
+	  // After a short delay the configuration is changed
+	  // in this example we will just add a banner plugin:
+	  compiler.apply(new webpack.BannerPlugin('A new banner'));
+	  // Recompile the bundle with the banner plugin:
+	  webpackDevMiddlewareInstance.invalidate();
+	}, 1000);
+	```
+
+* `waitUntilValid(callback)` - executes the `callback` if the bundle is valid or after it is valid again:
+	```js
+	var webpackDevMiddlewareInstance = webpackMiddleware(/* see example usage */);
+	app.use(webpackDevMiddlewareInstance);
+	webpackDevMiddleware.waitUntilValid(function(){
+	  console.log('Package is in a valid state');
+	});
+	```

middleware.js

@@ -95,7 +95,7 @@ module.exports = function(compiler, options) {
 	function ready(fn, req) {
 		if(state) return fn();
 		if(!options.noInfo && !options.quiet)
-			console.log("webpack: wait until bundle finished: " + req.url);
+			console.log("webpack: wait until bundle finished: " + (req.url || fn.name));
 		callbacks.push(fn);
 	}
 
@@ -193,9 +193,22 @@ module.exports = function(compiler, options) {
 
 	webpackDevMiddleware.getFilenameFromUrl = getFilenameFromUrl;
 
-	webpackDevMiddleware.invalidate = function() {
-		if(watching) watching.invalidate();
+	webpackDevMiddleware.waitUntilValid = function(callback) {
+		callback = callback || function(){};
+		if (!watching || !watching.running) callback();
+		else ready(callback, {});
 	};
+
+	webpackDevMiddleware.invalidate = function(callback) {
+		callback = callback || function(){};
+		if(watching) {
+			ready(callback, {});
+			watching.invalidate();
+		} else {
+			callback();
+		}
+	};
+
 	webpackDevMiddleware.close = function(callback) {
 		callback = callback || function(){};
 		if(watching) watching.close(callback);