Index: modules/color/color.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/color/color.module,v
retrieving revision 1.59
diff -u -r1.59 color.module
--- modules/color/color.module	27 May 2009 18:33:55 -0000	1.59
+++ modules/color/color.module	18 Jun 2009 23:16:24 -0000
@@ -169,8 +169,7 @@
   $info = color_get_info($theme);
 
   // Add Farbtastic color picker.
-  drupal_add_css('misc/farbtastic/farbtastic.css', array('preprocess' => FALSE));
-  drupal_add_js('misc/farbtastic/farbtastic.js', array('weight' => JS_LIBRARY));
+  drupal_add_js_library('farbtastic');
 
   // Add custom CSS and JS.
   drupal_add_css($base . '/color.css', array('preprocess' => FALSE));
Index: modules/system/system.api.php
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.api.php,v
retrieving revision 1.42
diff -u -r1.42 system.api.php
--- modules/system/system.api.php	18 Jun 2009 10:20:22 -0000	1.42
+++ modules/system/system.api.php	18 Jun 2009 23:16:26 -0000
@@ -183,6 +183,115 @@
 }
 
 /**
+ * Registers any JavaScript libraries associated with the module.
+ *
+ * Modules implementing this return an array of arrays. The key to each sub-array
+ * is the name of the library. Each library may contain the following items:
+ *
+ * - title: The human readable name of the library.
+ * - project_page: The URL of the library's website.
+ * - version: (required) A string value determining the version of the included
+ *   library. This is intentionally not a float because a version like "1.2.3"
+ *   is not a valid float. Use version_compare() to compare versions.
+ * - download: A URL to download the given version of the library.
+ * - js: An array of JavaScript elements to be processed when the library is
+ *   being added to the page. The array keys represents the $data parameter of
+ *   the drupal_add_js() call, and the value becomes the $options argument. If
+ *   the key is an integer, then the value becomes the $data parameter.
+ * - css: Similar to the "js" flag, provides an array of CSS elements to to be
+ *   processed when the library is being added the the page.
+ * - libraries: An array of dependent libraries that will also be added when
+ *   processing the given library. The array key is the name of the library,
+ *   while the value is an array of additional arguments that will be passed
+ *   during the call to drupal_add_js_library().
+ * - add: An array of function handlers that will called when this library is
+ *   processed on the page.
+ *
+ * @return
+ *   An array defining any JavaScript libraries associated with the module.
+ * @see system_js_libraries()
+ */
+function hook_js_libraries() {
+  // Library One.
+  $libraries['library-1'] = array(
+    'title' => 'Library One',
+    'website' => 'http://example.com/library-1',
+    // Note that this is a string. Use version_compare() to compare.
+    'version' => '1.2',
+    'js' => array(
+      // Items that are just strings are interpreted as stright files. 
+      drupal_get_path('module', 'my_module') . '/library-1.js',
+    ),
+    'css' => array(
+      // By providing an array, it becomes the $options parameter during the
+      // drupal_add_js/drupal_add_css call.
+      drupal_get_path('module', 'my_module') . '/library-2.css' => array(
+        'type' => 'file',
+        'media' => 'screen',
+      ),
+    ),
+  );
+  // Library Two.
+  $libraries['library-2'] = array(
+    'title' => 'Library Two',
+    'website' => 'http://example.com/library-2',
+    'version' => '1.2',
+    'js' => array(
+      // JavaScript settings can be added by sending in an array.
+      array(
+        'type' => 'setting',
+        'data' => array('library-2' => TRUE),
+      ),
+    ),
+    // Any depending libraries can be added by using the "libraries" key.
+    'libraries' => array(
+      // Sending in a string will just add the depending library to the page.
+      'library-1',
+      // Sending in the library name along with an array of parameters will be
+      // sent in as additional arguments to drupal_add_js_library().
+      'library-3' => array(
+        'additional arguments',
+      )
+    ),
+    // The library add handlers are all called when the library is added to the
+    // page.
+    'add' => array(
+      // The function named "library_2_added" will be called when library-2 is
+      // added to the page. The arguments passed to this function are the
+      // additional arguments that were passed during the call to
+      // drupal_add_js_library().
+      'library_2_added',
+    ),
+  );
+  return $libraries;
+}
+
+/**
+ * Alters the JavaScript library registry.
+ *
+ * @param $libraries
+ *   The JavaScript library registry.
+ * @return
+ *   An array with the updated JavaScript library registry.
+ * @see hook_js_libraries()
+ */
+function hook_js_libraries_alter(&$libraries) {
+  // Update Library One to version 1.6.
+  if (isset($libraries['library-1'])) {
+    if ($libraries['library-1']['version'] < 1.6) {
+      // The version number and CSS/JS files will change.
+      $libraries['library-1']['version'] = 1.6;
+      $libraries['library-1']['js'] = array(
+        drupal_get_path('module', 'library_1_update') . '/library-1.js',
+      );
+      $libraries['library-1']['css'] = array(
+        drupal_get_path('module', 'library_1_update') . '/library-1.css',
+      );
+    }
+  }
+}
+
+/**
  * Perform alterations before a page is rendered.
  *
  * Use this hook when you want to add, remove, or alter elements at the page
Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.712
diff -u -r1.712 system.module
--- modules/system/system.module	16 Jun 2009 08:41:35 -0000	1.712
+++ modules/system/system.module	18 Jun 2009 23:16:27 -0000
@@ -789,6 +789,46 @@
 }
 
 /**
+ * Implementation of hook_js_libraries().
+ */
+function system_js_libraries() {
+  // jQuery.
+  $libraries['jquery'] = array(
+    'title' => 'jQuery',
+    'website' => 'http://jquery.com',
+    'version' => '1.3.2',
+    'js' => array(
+      'misc/jquery.js' => array('weight' => JS_LIBRARY - 2),
+    ),
+  );
+
+  // jQuery Form Plugin.
+  $libraries['jquery_form'] = array(
+    'title' => 'jQuery Form Plugin',
+    'website' => 'http://malsup.com/jquery/form/',
+    'version' => '2.16',
+    'js' => array(
+      'misc/jquery.form.js',
+    ),
+  );
+
+  // Farbtastic.
+  $libraries['farbtastic'] = array(
+    'title' => 'Farbtastic',
+    'website' => 'http://acko.net/dev/farbtastic',
+    'version' => '1.2',
+    'js' => array(
+      'misc/farbtastic/farbtastic.js',
+    ),
+    'css' => array(
+      'misc/farbtastic/farbtastic.css',
+    ),
+  );
+
+  return $libraries;
+}
+
+/**
  * Retrieve a blocked IP address from the database.
  *
  * @param $iid integer
Index: modules/simpletest/tests/common.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/common.test,v
retrieving revision 1.46
diff -u -r1.46 common.test
--- modules/simpletest/tests/common.test	12 Jun 2009 08:39:39 -0000	1.46
+++ modules/simpletest/tests/common.test	18 Jun 2009 23:16:25 -0000
@@ -425,7 +425,7 @@
   /**
    * Store configured value for JavaScript preprocessing.
    */
-  var $preprocess_js = NULL;
+  protected $preprocess_js = NULL;
 
   public static function getInfo() {
     return array(
@@ -437,19 +437,22 @@
 
   function setUp() {
     // Enable Locale and SimpleTest in the test environment.
-    parent::setUp('locale', 'simpletest');
+    parent::setUp('locale', 'simpletest', 'common_test');
 
     // Disable preprocessing
     $this->preprocess_js = variable_get('preprocess_js', 0);
     variable_set('preprocess_js', 0);
 
-    // Reset drupal_add_js() before each test.
+    // Reset drupal_add_js() and the library registry before each test.
     drupal_static_reset('drupal_add_js');
+    drupal_static_reset('drupal_get_js_library');
   }
 
   function tearDown() {
     // Restore configured value for JavaScript preprocessing.
     variable_set('preprocess_js', $this->preprocess_js);
+    // Clear any messages.
+    drupal_get_messages();
     parent::tearDown();
   }
 
@@ -541,6 +544,41 @@
   }
 
   /**
+   * Checks to make sure that JavaScript library registry is built correctly.
+   */
+  function testLibraryRegistry() {
+    $libraries = drupal_get_js_library();
+    $this->assertTrue(isset($libraries['farbtastic']) && isset($libraries['form']), t('The JavaScript library registry is built correctly.'));
+  }
+
+  /**
+   * Adds a JavaScript library to the page and tests for both it and its CSS.
+   */
+  function testLibraryRender() {
+    drupal_add_js_library('farbtastic');
+    $javascript = drupal_get_js();
+    $stylesheets = drupal_get_css();
+    $this->assertTrue(strpos($javascript, 'misc/farbtastic/farbtastic.js') > 0, t('JavaScript libraries are rendered to the page.'));
+    $this->assertTrue(strpos($stylesheets, 'misc/farbtastic/farbtastic.css') > 0, t('JavaScript libraries render their CSS to the page.'));
+  }
+
+  /**
+   * Adds a JavaScript library to the page and alters it.
+   *
+   * @see common_test_js_libraries_alter()
+   */
+  function testLibraryAlter() {
+    // Empty out messages.
+    drupal_get_messages();
+
+    // Add farbtastic, which will fire common_test_js_alter().
+    drupal_add_js_library('farbtastic');
+    $library = drupal_get_js_library('farbtastic');
+    $this->assertTrue(array_search('common_test_js_library_add', $library['add']) !== FALSE, t('JavaScript libraries are alterable.'));
+    $this->assertTrue(strpos(theme('status_messages'), t('Add callback for the @library library fired.', array('@library' => 'farbtastic'))) !== FALSE, t('JavaScript library "add" callbacks are fired.'));
+  }
+
+  /**
    * Test adding a JavaScript file with a different weight.
    */
   function testDifferentWeight() {
Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.924
diff -u -r1.924 common.inc
--- includes/common.inc	18 Jun 2009 16:03:30 -0000	1.924
+++ includes/common.inc	18 Jun 2009 23:16:23 -0000
@@ -2779,15 +2779,6 @@
           'scope' => 'header',
           'weight' => JS_LIBRARY,
         ),
-        'misc/jquery.js' => array(
-          'data' => 'misc/jquery.js',
-          'type' => 'file',
-          'scope' => 'header',
-          'weight' => JS_LIBRARY - 2,
-          'cache' => TRUE,
-          'defer' => FALSE,
-          'preprocess' => TRUE,
-        ),
         'misc/drupal.js' => array(
           'data' => 'misc/drupal.js',
           'type' => 'file',
@@ -2798,6 +2789,8 @@
           'preprocess' => TRUE,
         ),
       );
+      // jQuery itself is registered as a library.
+      drupal_add_js_library('jquery');
     }
 
     switch ($options['type']) {
@@ -2954,6 +2947,118 @@
 }
 
 /**
+ * Adds multiple JavaScript files and CSS files for a JavaScript library.
+ *
+ * A JavaScript library could consist of a jQuery plugin, a separate JavaScript
+ * framework (such as Prototype or MooTools), or a library such as a WYSIWYG
+ * editor. Any time that there are multiple versions of a JavaScript package
+ * then it should be added via hook_js_libraries() and drupal_add_js_library().
+ * This allows other modules to check the version of the library, as well as
+ * modify it if different versions are required.
+ *
+ * @param $library
+ *   The name of the JavaScript library to add.
+ * @param ...
+ *   Additional arguments to pass to the add handlers associated with the
+ *   library.
+ * @return
+ *   An array containing the results from calling all the add handlers. The key
+ *   of the array is the add handler name, while the value is what was returned
+ *   from the call.
+ * @see hook_js_libraries()
+ * @see hook_js_libraries_alter()
+ */
+function drupal_add_js_library($library) {
+  $library = drupal_get_js_library($library);
+  if (!isset($library)) {
+    return NULL;
+  }
+  // Add all the JavaScript, stylesheets and dependent libraries.
+  foreach (array('libraries', 'js', 'css') as $type) {
+    if (isset($library[$type]) && is_array($library[$type])) {
+      foreach ($library[$type] as $data => $options) {
+        // If the value is not an array, it's a filename or library name and
+        // passed as the first (and only) argument.
+        if (!is_array($options)) {
+          $data = $options;
+          $options = array();
+        }
+        // When drupal_add_js with 'type' => 'setting' is called, the first
+        // parameter ($data) is an array. Arrays can't be keys in PHP, so we
+        // have to get $data from the value array.
+        if (is_numeric($data)) {
+          $data = $options['data'];
+          unset($options['data']);
+        }
+        // All libraries are given a weight of JS_LIBRARY by default.
+        if (!isset($options['weight'])) {
+          $options['weight'] = JS_LIBRARY;
+        }
+        // Change the 'libraries' key to 'js_library' to match the function.
+        $type = $type == 'libraries' ? 'js_library' : $type;
+        call_user_func('drupal_add_' . $type, $data, $options);
+      }
+    }
+  }
+
+  // Call all of the add handlers associated with the library.
+  $output = array();
+  if (isset($library['add']) && is_array($library['add'])) {
+    foreach ($library['add'] as $function) {
+      if (drupal_function_exists($function))  {
+        // Invoke the add handler, passing in the additional parameters.
+        $args = func_get_args();
+
+        // Remove the library name from the arguments before calling the handler.
+        $output[$function] = call_user_func_array($function, $args);
+      }
+    }
+  }
+  return $output;
+}
+
+/**
+ * Retrieves information from the JavaScript library registry.
+ *
+ * @param $library
+ *   (optional) If given, will provide the JavaScript library information for
+ *   just the given library name.
+ * @return
+ *   Returns all available JavaScript libraries, or the requested one from
+ *   the $library parameter.
+ * @see drupal_add_js_library()
+ * @see hook_js_libraries()
+ */
+function drupal_get_js_library($library = NULL) {
+  $libraries = &drupal_static(__FUNCTION__);
+
+  if (!isset($libraries)) {
+    if ($cache = cache_get('js_libraries')) {
+      $libraries = $cache->data;
+    }
+    else {
+      // Invoke hook_js_libraries() to create the library registry.
+      $libraries = module_invoke_all('js_libraries');
+
+      // Invoke hook_js_libraries_alter() to allow modification of the
+      // registry. This is helpful to allow modules to update any libraries
+      // to later versions.
+      drupal_alter('js_libraries', $libraries);
+
+      // Save the registry to the cache.
+      cache_set('js_libraries', $libraries);
+    }
+  }
+
+  if (isset($library)) {
+    return isset($libraries[$library]) ? $libraries[$library] : NULL;
+  }
+  else {
+    return $libraries;
+  }
+}
+
+/**
  * Assist in adding the tableDrag JavaScript behavior to a themed table.
  *
  * Draggable tables should be used wherever an outline or list of sortable items
Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.342
diff -u -r1.342 form.inc
--- includes/form.inc	18 Jun 2009 15:48:13 -0000	1.342
+++ includes/form.inc	18 Jun 2009 23:16:24 -0000
@@ -2002,7 +2002,7 @@
   // Adding the same javascript settings twice will cause a recursion error,
   // we avoid the problem by checking if the javascript has already been added.
   if ((isset($element['#ahah']['callback']) || isset($element['#ahah']['path'])) && isset($element['#ahah']['event']) && !isset($js_added[$element['#id']])) {
-    drupal_add_js('misc/jquery.form.js', array('weight' => JS_LIBRARY));
+    drupal_add_js_library('jquery_form');
     drupal_add_js('misc/ahah.js');
 
     $ahah_binding = array(
Index: modules/simpletest/tests/common_test.module
===================================================================
RCS file: modules/simpletest/tests/common_test.module
diff -N modules/simpletest/tests/common_test.module
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ modules/simpletest/tests/common_test.module	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,19 @@
+<?php
+// $Id$
+
+/**
+ * Implementation of hook_js_libraries_alter().
+ */
+function common_test_js_libraries_alter(&$libraries) {
+  // Set an "add" callback when farbtastic is added to the page..
+  if (isset($libraries['farbtastic'])) {
+    $libraries['farbtastic']['add'][] = 'common_test_js_library_add';
+  }
+}
+
+/**
+ * Add callback for the Farbtastic plugin.
+ */
+function common_test_js_library_add($library) {
+  drupal_set_message(t('Add callback for the @library library fired.', array('@library' => $library)));
+}
Index: modules/simpletest/tests/common_test.info
===================================================================
RCS file: modules/simpletest/tests/common_test.info
diff -N modules/simpletest/tests/common_test.info
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ modules/simpletest/tests/common_test.info	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,8 @@
+; $Id$
+name = "Common Test"
+description = "Support module for core Drupal functionality tests."
+core = 7.x
+package = Testing
+files[] = common_test.module
+version = VERSION
+hidden = TRUE