expose getLocalIdent (#357)

* expose getLocalIdent

* add test & docs

Author: longlho

README.md

@@ -108,6 +108,27 @@ You can use `:local(#someId)`, but this is not recommended. Use classes instead
 
 You can configure the generated ident with the `localIdentName` query parameter (default `[hash:base64]`). Example: `css-loader?localIdentName=[path][name]---[local]---[hash:base64:5]` for easier debugging.
 
+You can also specify the absolute path to your custom `getLocalIdent` function to generate classname based on a different schema. Note that this requires `webpack@2` since to be able to pass function in. For example:
+
+```js
+{
+    test: /\.css$/,
+    loaders: [
+        {
+            loader: 'css-loader',
+            query: {
+                modules: true,
+                importLoaders: 1,
+                getLocalIdent: function (loaderContext, localIdentName, localName, options) {
+                  return 'whatever_random_class_name'
+                }
+            }
+        }
+    ]
+},
+```
+
+
 Note: For prerendering with extract-text-webpack-plugin you should use `css-loader/locals` instead of `style-loader!css-loader` **in the prerendering bundle**. It doesn't embed CSS but only exports the identifier mappings.
 
 ### CSS Modules

lib/processCss.js

@@ -132,7 +132,6 @@ var parserPlugin = postcss.plugin("css-loader-parser", function(options) {
 });
 
 module.exports = function processCss(inputSource, inputMap, options, callback) {
-
 	var query = options.query;
 	var root = query.root;
 	var context = query.context;
@@ -141,6 +140,8 @@ module.exports = function processCss(inputSource, inputMap, options, callback) {
 	var forceMinimize = query.minimize;
 	var minimize = typeof forceMinimize !== "undefined" ? !!forceMinimize : options.minimize;
 
+	var customGetLocalIdent = query.getLocalIdent || getLocalIdent;
+	
 	var parserOptions = {
 		root: root,
 		mode: options.mode,
@@ -166,8 +167,8 @@ module.exports = function processCss(inputSource, inputMap, options, callback) {
 		extractImports(),
 		modulesValues,
 		modulesScope({
-			generateScopedName: function(exportName) {
-				return getLocalIdent(options.loaderContext, localIdentName, exportName, {
+			generateScopedName: function generateScopedName (exportName) {
+				return customGetLocalIdent(options.loaderContext, localIdentName, exportName, {
 					regExp: localIdentRegExp,
 					hashPrefix: query.hashPrefix || "",
 					context: context

test/customGetLocalIdentTest.js

@@ -0,0 +1,19 @@
+/*globals describe */
+
+var testLocals = require("./helpers").testLocals;
+
+describe("customGetLocalIdent", function() {
+	testLocals("should return only locals",
+		".abc :local(.def) { color: red; } :local .ghi .jkl { color: blue; }",
+		{
+			def: "foo",
+			ghi: "foo",
+			jkl: "foo"
+		},
+        {
+            getLocalIdent: function () {
+                return 'foo'
+            }
+        }
+	);
+});