Merge basic webpack 2 support #225

# By Alexander Wesolowski (1) and Jan Nicklas (1)
* commit 'c883a8663c07da04cb6b713bca45ed65a93f7e5c':
  Move template.js into loader.js
  Fix Webpack2 compatibility. Closes #213.

lib/loader.js

@@ -20,8 +20,31 @@ module.exports = function (source) {
   if (/\.js$/.test(this.request)) {
     return source;
   }
-  // Use underscore for a minimalistic loader
+
+  // The following part renders the tempalte with lodash as aminimalistic loader
+  //
+  // Get templating options
   var options = loaderUtils.parseQuery(this.query);
-  var template = _.template(source, options);
-  return 'var _ = require(' + loaderUtils.stringifyRequest(this, require.resolve('lodash')) + ');module.exports = ' + template;
+  // Webpack 2 does not allow with() statements, which lodash templates use to unwrap
+  // the parameters passed to the compiled template inside the scope. We therefore
+  // need to unwrap them ourselves here. This is essentially what lodash does internally
+  // To tell lodash it should not use with we set a variable
+  var template = _.template(source, _.defaults(options, { variable: 'data' }));
+  // All templateVariables which should be available
+  // @see HtmlWebpackPlugin.prototype.executeTemplate
+  var templateVariables = [
+    'webpack',
+    'webpackConfig',
+    'htmlWebpackPlugin'
+  ];
+  return 'var _ = require(' + loaderUtils.stringifyRequest(this, require.resolve('lodash')) + ');' +
+    'module.exports = function (templateParams) {' +
+      // Declare the template variables in the outer scope of the
+      // lodash template to unwrap them
+      templateVariables.map(function (variableName) {
+        return 'var ' + variableName + ' = templateParams.' + variableName;
+      }).join(';') + ';' +
+      // Execute the lodash template
+      'return (' + template.source + ')();' +
+    '}';
 };