Allow overriding UidAndTokenSerializer's behaviour

[Ou7law007]

Currently, UidAndTokenSerializer validates both fields uid and token at once and there's no way to reuse its code, because it doesn't allow overriding the validation of a single field without the other (either uid AND token or neither).

This change splits the validation into the respective fields to allow reusage. In my case, I needed to reuse UidAndTokenSerializer with a different token logic but with the same uid logic.

c74d590
@konradhalas left a comment 3 years ago that I do not quite understand:
# uid validation have to be here, because validate_<field_name>
# doesn't work with modelserializer

But UidAndTokenSerializer does not inherit from modelserializer!

For me the field validation works fine. It's also the same thing in the example provided by rest_framework, see: https://www.django-rest-framework.org/api-guide/serializers/#field-level-validation

I also left a comment at validate_token regarding the self.user. The reason I did not use any of the alternatives I mentioned is that if it broke in the future, then rest_framework must have had major changes that shouldn't go unspotted in that specific method.

Also, is it possible to update the pip repository? https://pypi.org/project/djoser/
Released: Oct 30, 2020
Plenty of updates have took place since then.

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If this doesn't get accepted and someone is looking for a workaround, to "reuse" UidAndTokenSerializer, you just need to provide your own def validate_token and def validate_uid and you'd have to copy the code of one of them (the one you don't want to override) from UidAndTokenSerializer for one field and provide your own code for the second one (you one you want to override).

You also need to override 'def validate' to do nothing:

class My_UidAndTokenSerializer(UidAndTokenSerializer):

def validate_uid(self, value):
    # either your own code or copy the code from 'UidAndTokenSerializer'
    return value

def validate_token(self, value):
    # either your own code or copy the code from 'UidAndTokenSerializer'
    return value

def validate(self, attrs):
    return attrs

At this point, it's not even called 'reuse', so... 🍡