Add dirname of current src file to rewriter function arguments.

Gruntfile.js

@@ -9,6 +9,9 @@
 'use strict';
 
 module.exports = function(grunt) {
+  var path = require('path'),
+      url = require('url');
+
   grunt.initConfig({
 
     jshint: {
@@ -54,6 +57,29 @@ module.exports = function(grunt) {
         files: {
           'test/output/sample-custom-options.html': 'test/fixtures/sample.html'
         }
+      },
+      customRewriter: {
+        options: {
+          base: false,
+          rewriter: function (originalURL, dirname) {
+            // If it looks like an absolute URL (based on a simplistic regexp match), don't do any rewrites.
+            if (!originalURL.match(/^(\w+:)?\/\//)) {
+              // If it's a relative path (no leading slash), assume it's relative to the src file and
+              // rebase it to be relative to the test/fixtures/ directory instead.
+              if (originalURL && originalURL[0] !== '/') {
+                originalURL = path.relative('test/fixtures/', path.resolve(dirname, originalURL));
+              }
+
+              return url.resolve('//cdn.example.com/', path.join('stuff/', originalURL));
+            }
+
+            return originalURL;
+          }
+        },
+        files: {
+          'test/output/css/custom-rewriter.css': 'test/fixtures/css/custom-rewriter.css',
+          'test/output/html/custom-rewriter.html': 'test/fixtures/html/custom-rewriter.html'
+        }
       }
     },
 

README.md

@@ -56,7 +56,7 @@ Example:
 cdnify: {
   someTarget: {
     options: {
-      rewriter: function (url) {
+      rewriter: function (url, dirnameOfSrc) {
         if (url.indexOf('data:') === 0) {
           return url;            // leave data URIs untouched
         } else {

tasks/cdnify.js

@@ -82,7 +82,13 @@ module.exports = function (grunt) {
 
     this.files.forEach(function (file) {
       var srcFile = file.src,
-          destFile = file.dest;
+          destFile = file.dest,
+          dirname = path.dirname(srcFile),
+          rewriteURLWithDirname;
+
+      rewriteURLWithDirname = function(url) {
+        return rewriteURL(url, dirname);
+      };
 
       if (typeof srcFile !== 'string') {
         if (srcFile.length > 1) {
@@ -98,7 +104,7 @@ module.exports = function (grunt) {
         // It's a CSS file
         var oldCSS = grunt.file.read(srcFile),
             newCSS = options.css ?
-              rewriteCSSURLs(oldCSS, rewriteURL) :
+              rewriteCSSURLs(oldCSS, rewriteURLWithDirname) :
               oldCSS;
 
         grunt.file.write(destFile, newCSS);
@@ -113,15 +119,15 @@ module.exports = function (grunt) {
           if (options.html.hasOwnProperty(search)) {
             var attr = options.html[search];
             if (attr) {
-              soup.setAttribute(search, attr, rewriteURL);
+              soup.setAttribute(search, attr, rewriteURLWithDirname);
             }
           }
         }
 
         // Update the URLs in any embedded stylesheets
         if (options.css) {
           soup.setInnerHTML('style', function (css) {
-            return rewriteCSSURLs(css, rewriteURL);
+            return rewriteCSSURLs(css, rewriteURLWithDirname);
           });
         }
 

test/cdnify_test.js

@@ -30,6 +30,26 @@ exports.cdnify = {
     var expected = grunt.file.read('test/expected/sample-custom-options.html');
     test.equal(actual, expected);
 
+    test.done();
+  },
+
+  'HTML file including external CSS with custom rewriter function': function (test) {
+    test.expect(1);
+
+    var actual = grunt.file.read('test/output/html/custom-rewriter.html');
+    var expected = grunt.file.read('test/expected/html/custom-rewriter.html');
+    test.equal(actual, expected);
+
+    test.done();
+  },
+
+  'CSS file with custom rewriter function': function (test) {
+    test.expect(1);
+
+    var actual = grunt.file.read('test/output/css/custom-rewriter.css');
+    var expected = grunt.file.read('test/expected/css/custom-rewriter.css');
+    test.equal(actual, expected);
+
     test.done();
   }
 };

test/expected/css/custom-rewriter.css

@@ -0,0 +1,3 @@
+.image {
+  background: url('//cdn.example.com/stuff/images/custom-rewriter.jpg');
+}

test/expected/html/custom-rewriter.html

@@ -0,0 +1,11 @@
+<html>
+  <head>
+    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:400,400italic,700">
+    <link rel="icon" href="//cdn.example.com/stuff/favicon.ico">
+    <link rel="apple-touch-icon" href="//cdn.example.com/stuff/apple-touch-icon.png">
+    <link rel="stylesheet" href="//cdn.example.com/stuff/css/custom-rewriter.css">
+  </head>
+
+  <body>
+  </body>
+</html>

test/fixtures/css/custom-rewriter.css

@@ -0,0 +1,3 @@
+.image {
+  background: url('../images/custom-rewriter.jpg');
+}

test/fixtures/html/custom-rewriter.html

@@ -0,0 +1,11 @@
+<html>
+  <head>
+    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:400,400italic,700">
+    <link rel="icon" href="/favicon.ico">
+    <link rel="apple-touch-icon" href="/apple-touch-icon.png">
+    <link rel="stylesheet" href="../css/custom-rewriter.css">
+  </head>
+
+  <body>
+  </body>
+</html>