commit 42c980a00955b4fbcf79edf759520dd48061f74d
Author: Dean Reilly <dean.reilly@gmail.com>
Date:   Wed Dec 12 22:05:30 2012 +0000

    1821548-new_changes

diff --git a/core/modules/config/config.admin.inc b/core/modules/config/config.admin.inc
index 8f88ae4..2a24190 100644
--- a/core/modules/config/config.admin.inc
+++ b/core/modules/config/config.admin.inc
@@ -41,9 +41,6 @@ function config_admin_sync_form(array &$form, array &$form_state, StorageInterfa
       continue;
     }
 
-    // Add the CSS for the inline diff.
-    $form['#attached']['css'][] = drupal_get_path('module', 'system') . '/system.diff.css';
-
     // @todo A table caption would be more appropriate, but does not have the
     //   visual importance of a heading.
     $form[$config_change_type]['heading'] = array(
@@ -65,38 +62,20 @@ function config_admin_sync_form(array &$form, array &$form_state, StorageInterfa
     }
     $form[$config_change_type]['list'] = array(
       '#theme' => 'table',
-      '#header' => array('Name'),
+      '#header' => array('Name', 'Operations'),
     );
 
     foreach ($config_files as $config_file) {
-      $form[$config_change_type]['list']['#rows'][] = array($config_file);
-
-      switch ($config_change_type) {
-        case 'change':
-          $fieldset_title = t('View changes of @config_file', array('@config_file' => $config_file));
-          break;
-
-        case 'create':
-          $fieldset_title = t('View added file @config_file', array('@config_file' => $config_file));
-          break;
-
-        case 'delete':
-          $fieldset_title = t('View removed file @config_file', array('@config_file' => $config_file));
-          break;
-      }
-
-      // Show the additions/changes/deletions in a nice collapsible fieldset.
-      $fieldset = array(
-        '#type' => 'fieldset',
-        '#title' => $fieldset_title,
-        '#collapsible' => TRUE,
-        '#collapsed' => TRUE,
-      );
-      $fieldset['diff'] = array(
-        '#markup' => config_diff($target_storage, $source_storage, $config_file),
-      );
       $form[$config_change_type]['list']['#rows'][] = array(
-        array('data' => $fieldset),
+        'name' => $config_file,
+        'operations' => array(
+          'data' => array(
+            '#type' => 'link',
+            '#title' => t('Diff'),
+            '#href' => 'admin/config/development/sync/diff/' . $config_file,
+            '#ajax' => array('dialog' => array('modal' =>TRUE)),
+          ),
+        ),
       );
     }
   }
@@ -147,3 +126,39 @@ function config_admin_import_form_submit($form, &$form_state) {
     drupal_set_message(t('The import failed due to an error. Any errors have been logged.'), 'error');
   }
 }
+
+/**
+ * Page callback: Shows diff of specificed configuration file.
+ *
+ * @param string $config_file
+ *   The name of the configuration file.
+ *
+ * @return string
+ *   Table showing a two-way diff between the active and staged configuration.
+ */
+function config_admin_diff_page($config_file) {
+  // Retrieve a list of differences between last known state and active store.
+  $source_storage = drupal_container()->get('config.storage.staging');
+  $target_storage = drupal_container()->get('config.storage');
+
+  // Add the CSS for the inline diff.
+  $output['#attached']['css'][] = drupal_get_path('module', 'system') . '/system.diff.css';
+
+  $output['title'] = array(
+    '#theme' => 'html_tag__h3',
+    '#tag' => 'h3',
+    '#value' => t('View changes of @config_file', array('@config_file' => $config_file)),
+  );
+
+  $output['diff'] = array(
+    '#markup' => config_diff($target_storage, $source_storage, $config_file),
+  );
+
+  $output['back'] = array(
+    '#type' => 'link',
+    '#title' => "Back to 'Synchornize configuration' page.",
+    '#href' => 'admin/config/development/sync',
+  );
+
+  return $output;
+}
diff --git a/core/modules/config/config.module b/core/modules/config/config.module
index a41fc09..7482171 100644
--- a/core/modules/config/config.module
+++ b/core/modules/config/config.module
@@ -48,6 +48,14 @@ function config_menu() {
     'access arguments' => array('synchronize configuration'),
     'file' => 'config.admin.inc',
   );
+  $items['admin/config/development/sync/diff/%'] = array(
+    'title' => 'Configuration file diff',
+    'description' => 'Diff between active and staged configuraiton.',
+    'page callback' => 'config_admin_diff_page',
+    'page arguments' => array(5),
+    'access arguments' => array('synchronize configuration'),
+    'file' => 'config.admin.inc',
+  );
   $items['admin/config/development/sync/import'] = array(
     'title' => 'Import',
     'type' => MENU_DEFAULT_LOCAL_TASK,