Bug 1928549: Fix API schema generation and 500 error on docs page

[moijes12]

This PR resolves a 500 error encountered when accessing the /docs/ and /api/schema/ endpoints. The issue was caused by incompatibilities between django-filter and djangorestframework's schema generation, as well as missing attributes in specific API views.

• Add TreeherderFilterBackend to implement missing get_schema_operation_parameters method in DjangoFilterBackend.
• Update DEFAULT_FILTER_BACKENDS and performance_data.py viewsets to use the new custom backend.
• Change PerformanceJobViewSet to inherit from ViewSet to avoid serializer_class assertion errors.
• Fix AttributeError in PerfCompareResults.get_serializer_class when request is None during schema generation.
• Rename typos in DetailsPanel.jsx and PerformanceJobViewSet for consistency.

@jmaher @gmierz

Fixes Bug 1928549

[moijes12]

@bhearsum Please can you review this if you get some time

[bhearsum]

I'm not actually a reviewer for Treeherder.... @Archaeopteryx ?

[moijes12]

No problem. Thanks @bhearsum

[gmierz]

Thank you for fixing these typos while you were here :)

[gmierz]

Hi @moijes12, thanks for looking into this!

I see that there was a patch for django-filter that should have added the get_schema_operation_parameters quite a while ago here: https://github.com/carltongibson/django-filter/pull/1086/files

So it seems odd that we still need a custom filter backend for it - would you know why? It makes me wonder if there's a better solution that could fix this issue for us.

[moijes12]

Thanks @gmierz for your feedback

I did try with the latest django-filter (version 25.2) and it did seem odd to me that it still did not work. However, I will give it a second shot and get back.

[moijes12]

@gmierz

I was able to fix the issue. django-filter recommends usage of drf-spectacular for generating schemas with DRF (see). The schema generation methods of the DRF related DjangoFilterBackend were deprecated in django-filter version 23.0. I have updated the DEFAULT_SCHEMA_CLASS and the updated the views.

As part of my latest change, I have:

• Reverted my previous commit
• Added drf_spectacular to the requirements
• Updated settings.py to use drf_spectacular in the installed apps as well as for REST schema generation
• Updated the /webapp/api/urls.py to use drf_spectacular.views.SpectacularAPIView for schema
• Updated the RedocApp component's specUrl to point to ?format=json as drf_spectacular cannot use ?format=openapi-json
• Updated typos as done previously