WP-853: Adjust apcd backend to handle permissions error and general errors properly

[chandra-tacc]

Overview

Issues before this PR:

• Template is viewable even without permissions, and api fails with 302.
• User does not have a clear message.
• If api requests fail, then sometimes the response is not json.

Related

WP-853

Changes

1. Separate template and api views in backend.
2. For template view do a redirect to '/'
3. For api view use Json Response with 403.
4. To allow api clean code, add a mixin for common auth conditions and add baseview to allow error handling

Testing

Follow are the page permissions:
APCD_ADMIN: all pages
SUBMITTER ADMIN: Register menu and Submissions Menu
SUBMITTER USER: Submissions menu

go admin pages, do the following

1. remove staff, super user, and any apcd groups.
2. save

to restore:

Use this code to enable superuser after removing access

python manage.py shell

and then

from django.contrib.auth import get_user_model
my_user = get_user_model().objects.get(username="<username>")
my_user.is_staff = True
my_user.is_superuser = True
my_user.save()

Test cases:

1. As admin all pages work
2. As submitter_user:
   Only submissions menu items work.
   Manually try to go to

   http://localhost:8000/administration/list-registration-requests/
   http://localhost:8000/administration/list-exceptions
   http://localhost:8000/administration/list-extensions
   http://localhost:8000/administration/list-submissions
   http://localhost:8000/register/list-registration-requests/
   http://localhost:8000/register/list-registration-requests/api
   

and see that you are redirected to home

3. As submitter_admin:
   See that both submissions menu and registrations work
   Manually try to go to

   http://localhost:8000/administration/list-registration-requests/
   http://localhost:8000/administration/list-exceptions
   http://localhost:8000/administration/list-extensions
    http://localhost:8000/administration/list-submissions
   

and see that you are redirected to home

[sophia-massie]

Tested and LGTM! Thanks for the work on this. We may want to remove the List Registrations from the CMS Register navigation for submitter user role if they will just be redirected, but this PR is reflecting prod so not a blocker.

[chandra-tacc]

Tested and LGTM! Thanks for the work on this. We may want to remove the List Registrations from the CMS Register navigation for submitter user role if they will just be redirected, but this PR is reflecting prod so not a blocker.

Yes, that is a good idea. That would be a CMS side change and not in this code base, can be addressed separately.