Allow for a custom replace function

README.md

@@ -135,6 +135,40 @@ return gulp.src(opt.distFolder + '**/*.js')
     .pipe(gulp.dest(opt.distFolder));
 ```
 
+#### options.replacer
+Type: `Function`
+
+Default: `return contents.split(unreved).join(reved)`
+
+Use a custom method for replacing the file references. The function is provided
+with four arguments: the `contents` of the file being processed, the `unreved`
+filename whose references are being searched for, the `reved` filename with which
+they should be replaced, and the (Vinyl) `file` object that is being searched.
+Note that the `replacer` function is called after `modifyUnreved` and `modifyReved`
+have been applied.
+
+The function should return the new `contents`.
+
+For example if you only want to replace the reference if it's between (double)
+quotes in css files, you could do the following:
+
+```js
+function replaceFn(contents, unreved, reved, file) {
+    if (file.path.indexOf('.css') > -1) {
+        return contents.replace(new RegExp('"' + unreved + '"', 'g'), '"' + reved + '"');
+    } else {
+        return contents;
+    }
+}
+
+return gulp.src(opt.distFolder + '**/*.js')
+    .pipe(revReplace({
+        manifest: manifest,
+        replacer: replaceFn
+    }))
+    .pipe(gulp.dest(opt.distFolder));
+```
+
 ## Contributors
 
 - Chad Jablonski

index.js

@@ -81,7 +81,7 @@ function plugin(options) {
         renames.forEach(function replaceOnce(rename) {
           var unreved = options.modifyUnreved ? options.modifyUnreved(rename.unreved) : rename.unreved;
           var reved = options.modifyReved ? options.modifyReved(rename.reved) : rename.reved;
-          contents = contents.split(unreved).join(reved);
+          contents = options.replacer ? options.replacer(contents, unreved, reved, file) : contents.split(unreved).join(reved);
           if (options.prefix) {
             contents = contents.split('/' + options.prefix).join(options.prefix + '/');
           }

test.js

@@ -538,3 +538,51 @@ describe('modifyUnreved and modifyReved options', function() {
         stream.end();
     });
 });
+
+describe('replacer option', function() {
+    it('should use the provided replacer method', function(cb) {
+        var manifest = es.readArray([
+            new gutil.File({
+                path: '/project/rev-manifest.json',
+                contents: new Buffer(JSON.stringify({
+                    'css/style.css': 'css/style-12345.css'
+                }))
+            })
+        ]);
+
+        function replacerFn(contents, unreved, reved, file) {
+          assert(
+            file.path === 'index.html',
+            'The provided file object should be the file being searched for references'
+          );
+          return contents.replace(unreved, '~' + reved + '~');
+        }
+
+        var stream = revReplace({
+            manifest: manifest,
+            replacer: replacerFn
+        });
+
+        var replacedCSSFilePattern = /~css\/style-12345\.css~/;
+
+        stream.on('data', function(file) {
+            var contents = file.contents.toString();
+
+            assert(
+                replacedCSSFilePattern.test(contents),
+                'The renamed CSS file\'s name should be replaced by the replacer function'
+            );
+        });
+
+        stream.on('end', function() {
+            cb();
+        });
+
+        stream.write(new gutil.File({
+            path: 'index.html',
+            contents: new Buffer(htmlFileBody)
+        }));
+
+        stream.end();
+    });
+});