Adding GeneratedField to supported types for RangeNumericFilter

[yarimiz]

I have a use case where I wish to have a RangeNumericFilter for a GeneratedField.
This was not allowed until now. This PR is to allow this configuration.

I had not added any extra validations to check whether the actual value of the GeneratedField is numeric, as I don't think this should be done by unfold. Let me know if you think otherwise.

[lukasvinclav]

What type is GeneratedField in database?

[Zerotask]

What type is GeneratedField in database?

depends on what you pass for output_field. For example output_field=models.CharField(max_length=16) would be a VARCHAR(16)

[lukasvinclav]

if the column type is variable, how we are checking if this field can be used for numeric filtering?

[yarimiz]

One way we can resolve this is to make sure the output_field of the GeneratedField is one of the already supported field types (DecimalField, IntegerField, FloatField, AutoField)

[lukasvinclav]

exactly, if you can, please update the PR

[yarimiz]

Sure, working on that now

[lukasvinclav]

please ensure that your change is going to be backward compatible as well. I guess on django pre 5.x import fill fail.

[yarimiz]

what is the best appraoch you suggest for safe importing? I thought either importing only if django is >=5.0 at the top level, or do the whole importing the GeneratedField.output_field checks inside a try-except and handling the ImportError if raised.

[lukasvinclav]

In the past I used the approach below but if you are aware of something more elegant, I'm open to incorporate it everywhere:

https://github.com/unfoldadmin/django-unfold/blob/main/src/unfold/admin.py#L59-L65

[yarimiz]

I don't think my appraoch is more elegant, but just might be more "local"

try:
    from django.db.models import GeneratedField
     if isinstance(field, GeneratedField) and isinstance(
        field.output_field, (DecimalField, IntegerField, FloatField, AutoField)
    ):
        raise TypeError(
            f"Class {type(field.output_field)} of the output_field is not supported for {self.__class__.__name__}."
        )
except ImportError:
    pass

Tell me which you prefer and I'll implement it

[lukasvinclav]

Your snippet looks good as well.

[yarimiz]

Please take a look at the final code when you have the time :)

[lukasvinclav]

I played with simpler check for backward compatibility. What do you think about the solution below. Would you mind to test it?

if not isinstance(
    field.output_field if hasattr(field, "output_field") else field,
    (DecimalField, IntegerField, FloatField, AutoField),
):
    raise TypeError(
        f"Class {type(self.field)} is not supported for {self.__class__.__name__}."
    )