Fix missing object buttons for keys.

mayan/apps/navigation/classes.py

@@ -196,7 +196,10 @@ class Link(object):
         resolved_link.text = self.text
 
         view_name = Variable('"{}"'.format(self.view))
-        if isinstance(self.args, list):
+        if isinstance(self.args, list) or isinstance(self.args, tuple):
+            # TODO: Don't check for instance check for iterable in try/except
+            # block. This update required changing all 'args' argument in
+            # links.py files to be iterables and not just strings.
             args = [Variable(arg) for arg in self.args]
         else:
             args = [Variable(self.args)]