fix openapi fields rendering for range type filters

[A-Ashiq]

This fix is aimed at Issue 1292.

Within the get_schema_fields method on DjangoFilterBackend. The coreapi field named tuples are made by looping over the filters retrieved from the filterset class. This change adds a check to see if there is widget which has been declared which in turn will provide us with the suffixes used to build range type fields. If no suffixes have been declared or the list is empty, then a single field will be rendered as normal with reference to the field_name.

For example, the DateFromToRangeFilter requires 2 fields to be rendered on swagger. If say the field name is created_at then we would expect created_at_after and created_at_before to be rendered. The current implementation will only render a single field as created_at which won't work.

[A-Ashiq]

This will be followed up with tests + a fix for my use of f-strings

[carltongibson]

Hi @A-Ashiq. Here you're adjusting the old CoreAPI generation, rather than the OpenAPI fields that we need.

[A-Ashiq]

@carltongibson can this be reviewed again?

[heavenshell]

Hi. Is there any news about this?

[lparolari]

Hi. Any news on this?

Why the PR cannot be merged? This will help a lot.

Thank you!

[carltongibson]

As per #1432 the in-built schema support is going to be deprecated in the next version.

Rather, I recommend you migrate to use drf-spectacular, which is much more fully featured, and under active development.

https://drf-spectacular.readthedocs.io/en/latest/readme.html

If for some reason you're not able to use drf-spectacular you can copy the django_filters.rest_framework.backends.DjangoFilterBackend into your own project to customise as needed. (But use drf-spectacular.)

Thanks.