Class-based generic views dropped support for X-Object-* headers

[Russell Keith-Magee]

The function-based generic views use the django.core.xheaders.populate_xheaders method to attach a X-Object-Type and X-Object-Id header to responses served by a generic view. This debug information in the response

Django needs to either:

1. Deprecate and remove populate_xheaders, or
2. Add X-Object-Type and X-Object-Id header support to class-based generic views.

If we choose to do (2), then we can't just wrap the generic view response in populate_xheaders, because we don't have access to the response object at the time at which we determine the object that is in use. It will probably be necessary to add generic support to define headers anywhere in the lifespan of a request, and then apply those headers when the response is constructed; i.e., in much the same way that self.request is available throughout the lifespan of a request, make self.response_headers available throughout the lifespan of a request.

[Russell Keith-Magee]

This came to my attention in the process of deprecating function-based generic views; the regressiontests.special_headers regression test contains specific tests for the X-Object-Type headers, and the test wasn't directly convertible to generic views.

[Russell Keith-Magee]

After a brief discussion with Jannis on IRC, option (2) seems like the best approach.

[Russell Keith-Magee]

In [15998]:

Silenced DeprecationWarning raised by tests for populate_xheaders tests. Refs #15741

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Aymeric Augustin]

Is this ticket still relevant?

AFAICT, we removed the function-based generic views without providing a replacement for this feature.

[Aymeric Augustin]

Since we did remove the feature (option 1), I'm going to mark this fixed... Please reopen if you want this feature added to the class based generic views (I don't know the use case).