Makes sure ajax-updated rows still get correct actions allowed.

Also moved some logic that pertained to BatchAction from
BaseAction to BatchAction where it belonged.

Fixes bug 944853.

Change-Id: I24f590f0b4320a0cc58d954398673a8fa75a49b6

horizon/tables/actions.py

@@ -53,9 +53,6 @@ def allowed(self, request, datum):
         return True
 
     def _allowed(self, request, datum):
-        """ Default allowed checks for certain actions """
-        if isinstance(self, BatchAction) and not self.table.data:
-            return False
         return self.allowed(request, datum)
 
     def update(self, request, datum):
@@ -427,6 +424,13 @@ def __init__(self):
                                            self._conjugate('plural'))
         super(BatchAction, self).__init__()
 
+    def _allowed(self, request, datum=None):
+        # Override the default internal action method to prevent batch
+        # actions from appearing on tables with no data.
+        if not self.table.data and not datum:
+            return False
+        return super(BatchAction, self)._allowed(request, datum)
+
     def _conjugate(self, items=None, past=False):
         """
         Builds combinations like 'Delete Object' and 'Deleted