fixed the source function issue

Author: nutboltu

README.md

@@ -1,4 +1,5 @@
-## PostCss Wrapper Loader
+## PostCss Wrapper Loader for Webpack
+
 ### Example
 This plugin wraps all the cssClasses in a css file with a prefix class while webpack bundled. It helps to scope a specific css file with a prefix class
 
@@ -18,7 +19,7 @@ In the webpack config file initialize the loader
 const PostCssWrapper = require('postcss-wrapper-loader');
 ```
 
-then within your webpack plugins:
+add this plugin in webpack plugins
 ```
   plugins: [
     new ExtractTextWebpackPlugin('styles.css'),

index.js

@@ -35,10 +35,10 @@ PostCssWrapper.prototype.apply = function(compiler) {
     const source = assets[file].source();
     const processor = postCss([postCssWrapperPlugin(container)]);
 
-    processor.process(source).then(function(result){
+    processor.process(source).then(function(result) {
       compilation.assets[file] = {
-        source: result.css,
-      size: result.css.length
+        source: function() { return result.css; },
+        size: function() { return result.css.length; }
   };
     callback();
   }, callback);

package.json

@@ -1,6 +1,6 @@
 {
   "name": "postcss-wrapper-loader",
-  "version": "0.0.1",
+  "version": "0.0.2",
   "private": false,
   "description": "This plugin wraps all the cssClasses in a css file with a prefix class while webpack bundled. It helps to scope a specific css file with a prefix class",
   "main": "index.js",