Users should be able to configure API renderer_classes

Issue Summary

Users should be able to configure API renderer_classes, currently these are hardcoded to [JSONRenderer, BrowsableAPIRenderer]: https://github.com/wagtail/wagtail/blob/1958bba2476c32069acafd6837514749a4d3ceea/wagtail/api/v2/views.py#L26

Steps to Reproduce

Configure pages endpoint as usual, but do not include rest_framework in the INSTALLED_APPS. Try to open configured endpoint in the browser, the app will throw an exception:

Internal Server Error: /rest/p/
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/usr/local/lib/python3.8/site-packages/django/core/handlers/base.py", line 145, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/usr/local/lib/python3.8/site-packages/django/core/handlers/base.py", line 143, in _get_response
    response = response.render()
  File "/usr/local/lib/python3.8/site-packages/django/template/response.py", line 105, in render
    self.content = self.rendered_content
  File "/usr/local/lib/python3.8/site-packages/rest_framework/response.py", line 70, in rendered_content
    ret = renderer.render(self.data, accepted_media_type, context)
  File "/usr/local/lib/python3.8/site-packages/rest_framework/renderers.py", line 723, in render
    template = loader.get_template(self.template)
  File "/usr/local/lib/python3.8/site-packages/django/template/loader.py", line 19, in get_template
    raise TemplateDoesNotExist(template_name, chain=chain)
django.template.exceptions.TemplateDoesNotExist: rest_framework/api.html

Technical details

• Python Version: 3.8.2
• Django Version: 3.0
• Wagtail Version: 2.9

---

Currently I’m using this nasty trick:

from django.conf import settings
from wagtail.api.v2.views import PagesAPIViewSet
from wagtail.api.v2.router import WagtailAPIRouter

if not settings.DEBUG:
    from rest_framework.renderers import JSONRenderer

    class ProdPagesAPIViewSet(PagesAPIViewSet):
        renderer_classes = [JSONRenderer]

    PagesAPIViewSet = ProdPagesAPIViewSet

# Create the router. "wagtailapi" is the URL namespace
api_router = WagtailAPIRouter("wagtailapi")

api_router.register_endpoint("p", PagesAPIViewSet)

[m-aciek]

Hi, any updates on that?

It forces us to enable DRF browsable API, otherwise there’s an error raised, see https://stackoverflow.com/questions/61961099/wagtail-api-v2-django-template-exceptions-templatedoesnotexist.

It’s somewhat contrary to documentation which states

Optionally, you may also want to add rest_framework to INSTALLED_APPS. This would make the API browsable when viewed from a web browser but is not required for basic JSON-formatted output.

https://docs.wagtail.org/en/stable/advanced_topics/api/v2/configuration.html#enable-the-app

[marteinn]

Many thanks @narun4sk and @phptek. This is a design decision so I will raise the issue with the core team, will report back here when we have discussed.