og_context/og_context.module | 46 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/og_context/og_context.module b/og_context/og_context.module
index 55a8533..dd4561b 100644
--- a/og_context/og_context.module
+++ b/og_context/og_context.module
@@ -144,6 +144,18 @@ function og_context_og_context_negotiation_info() {
     'callback' => 'og_context_handler_comment',
     'menu path' => array('comment/reply/%', 'comment/%'),
   );
+  $providers['file-ajax'] = array(
+    'name' => t('File Ajax'),
+    'description' => t("Determine context by checking the form's node's group or the form's action parameters during file uploads."),
+    'callback' => 'og_context_handler_ajax',
+    'menu path' => array('file/ajax'),
+  );
+   $providers['system-ajax'] = array(
+    'name' => t('System Ajax'),
+    'description' => t("Determine context by checking the form's node's group or the form's action parameters during Ajax Call."),
+    'callback' => 'og_context_handler_ajax',
+    'menu path' => array('system/ajax'),
+  );
 
   return $providers;
 }
@@ -379,7 +391,12 @@ function og_context_provider_weight($provider) {
  */
 function og_context_determine_context($group_type, $item = NULL, $check_access = TRUE) {
   // Enable url and node context handlers by default.
-  $defaults = array('url' => -5, 'node' => -4);
+  $defaults = array(
+    'url' => -5,
+    'node' => -4,
+    'file-ajax' => -3,
+    'system-ajax' => -2,
+  );
   if (!$enabled_providers = variable_get('og_context_negotiation_group_context', $defaults)) {
     return;
   }
@@ -648,3 +665,30 @@ function _og_context_views_page_access($group_type, $perm, $group_id_arg = FALSE
     return og_user_access($group_type, $group['gid'], $perm);
   }
 }
+
+/**
+ * Context handler; Shared between file upload and system ajax calls.
+ *
+ * This only works for _existing_ entities, not during entity creation.
+ *
+ * @todo: Extract the logic in og_context_handler_url() for detection of group
+ * using entityreference_prepopulate and use that here.
+ */
+function og_context_handler_ajax() {
+  $item = menu_get_item();
+
+  if (strpos($item['path'], 'file/ajax') !== 0 && strpos($item['path'], 'system/ajax') !== 0) {
+    return;
+  }
+
+  list($form, $form_state) = ajax_get_form();
+
+  if (empty($form['#entity_type'])) {
+    return;
+  }
+  $entity_type = $form['#entity_type'];
+  if (empty($form_state[$entity_type])) {
+    return;
+  }
+  return _group_context_handler_entity($entity_type, $form_state[$entity_type]);
+}