panels(templates): avoid evaluating LazyObject

LazyObject is typically used for something expensive to evaluate, so avoid evaluating it just for showing it in the debug toolbar.

debug_toolbar/panels/templates/panel.py

@@ -96,10 +96,15 @@ def _store_template_info(self, sender, **kwargs):
  if pformatted is None:
  temp_layer = {}
  for key, value in context_layer.items():
+ # Do not force evaluating LazyObject
+ if hasattr(value, "_wrapped"):
+ # SimpleLazyObject has __repr__ which includes actual value
+ # if it has been already evaluated
+ temp_layer[key] = repr(value)
  # Replace any request elements - they have a large
  # Unicode representation and the request data is
  # already made available from the Request panel.
- if isinstance(value, http.HttpRequest):
+ elif isinstance(value, http.HttpRequest):
  temp_layer[key] = "<<request>>"
  # Replace the debugging sql_queries element. The SQL
  # data is already made available from the SQL panel.