Testing class-based views with custom context_object_name

Using Django Forms & APIs
1

I was following the docs at Advanced testing topics | Django documentation | Django with a CBV which has set a custom context_object_name (“reports” in my case).

If I try to access view.get_context_data() in my test class, I get the error:
AttributeError: ‘DashboardView’ object has no attribute ‘object_list’

I does work, if I specify my context_object_name here, too:
context = view.get_context_data(object_list=“reports”)

Although view is an instance of my CBV, so it does have access to context_object_name.
Is this something which can be added to Django, to check for this property?
If no object_list is passed, check if the class has a context_object_name set, otherwise set None.
This way I don’t have to double specify my context_object_name.

2

You can check for the existence of an attribute on a an object, and retrieve that attribute by name using Python’s hasattr and getattr functions.

3

Thank you for your message.

I’m aware of that. I’m asking if this could be a feature request for Django itself. So you don’t have to double specify such things.

4

I guess I’m not following what the issue is here then. You can interrogate the view for the existence of the context_object_name attribute, and then do whatever you need to do with that information.

It may be helpful if you posted the full code of the test you’re trying to run.

5

I’m not asking for my code, but for an addition to Django itself, because I think this is redundant.

class DashboardView(ListView):
    model = Report
    context_object_name = "reports"

class DashboardViewTest(TestCase):
    request = RequestFactory().get("dashboard")
    view = DashboardView()
    view.setup(request)

    context = view.get_context_data() # does not work

This will produce the error AttributeError: ‘DashboardView’ object has no attribute ‘object_list’

Django (not my code) could simply check, as I wrote above, for the existence of context_object_name, so I don’t have to specify it in my test (again):

class DashboardViewTest(TestCase):
    request = RequestFactory().get("dashboard")
    view = DashboardView()
    view.setup(request)

    context = view.get_context_data(object_list="reports") # this does work but is redundant

So currently I have to double specify reports, in my view and in my test, even though the view object in the test has access to context_object_name.

Does this make it more clear?

I’m writing here in this forum, because the Django docs says to ask here first before submitting a ticket.

6

Absolutely, thank you.

First, this specific situation you are encountering is due to the difference between a DetailView (as being shown in the docs) and a ListView.

In the sequence of events that occurs in a ListView, get_context_data is dependent upon being called within get. Or, more specifically, get_context_data shouldn’t be called until after get_queryset has been called, which is what sets self.object_list.

So the root issue here isn’t specifically naming object_list within your get_context_data, but that self.object_list hasn’t been set in those cases where you’re not explicitly passing object_list as a parameter.

If you add view.object_list = view.get_queryset() prior to context = view.get_context_data(), it will work.

Or, if you know that context_object_name is going to be set in the class:
context = view.get_context_data(object_list=view.context_object_name)

But as a side-note, I don’t consider this “redundant” in any meaningful sense of the word. You’re writing a test here, not adding to your core code. Some degree of repetition is going to occur as you are short-circuiting the normal flow of events through these views.

1 Like