Feature request: option in Meta to rename fields in ModelSerializer

[christophehenry]

As far as I know, there are 3 ways to serialize a Django model field under a different name:

• use serializers.ModelField
• use serializers.SerializerMethodField
• use the source parameter of fields.Field.

All of them are quite tedious. The first one necessitate to intantiate a least one instance of the model, which is a waste of resources and rather counter intuitive, the second necessitates to create accessors for every field and the third defeats the auto-mapping feature of ModelSerializer.

It would be nice if renaming a field was simpler. It could take the form of a renamed_fields attribute in ModelSerializer.Meta. Alternatively, ModelField can be modified to accept a model_field_name argument and fetch the model field based on this (although I have a preference for the first method).

I am ready to implement that feature with a little guidance.

[auvipy]

can you share some code sample/example of what you are suggesting?

[christophehenry]

Ok, let's take the following django model:

from django.db import models


class Connection(models.Model):
    date = models.DateTimeField(auto_now_add=True)
    user = organisation = models.ForeignKey(models.CASCADE)

And I'd like it serialized like this:

{
    "creation_date": "…"
    "user": "…"
}

In this case, I just want the date field renamed creation_date.

Currently, one of the solution I have is:

from rest_framework import serializers


class OrganisationSerializer(serializers.HyperlinkedModelSerializer):
    creation_date = serializers.ModelField(model_field=Connection()._meta.get_field("date"))

    class Meta:
        model = Connection
        fields = ["creation_date", "user"]

For simple renames like this, it would be nice to have something like this instead:

from rest_framework import serializers


class OrganisationSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Connection
        fields = ["creation_date", "user"]
        renamed_fields = {"creation_date": "date"}

[auvipy]

I think you can simply rename it in the fields meta. so no other extra work or extra field attribute is not needed. you can easily change to fields = ["creation_date", "user"] from fields = ["date", "user"]

[christophehenry]

But that's not what I want to do. What I would like is, for instance Connection.date be serialized as creation_date using a simple declaration in Meta.

[awbacker]

A feature like this would be useful, so I could rename the output field. Currently you need to add a new field by that name on the serializer, and specify all fields explicitly.

I find myself wanting all the auto-generated field properties (max length, help text, etc) but only rename the field. I suppose an alternative would be to make creating a serializer field from a model field easier.

Perhaps something like this:

class User(Model):
    name = CharField()
    email_address = CharField(max_length=1000)

class UserSerializer(ModelSerializer):
    class Meta:
        model = User
        fields = ["name", "email"] # or "__all__"
        renamed_fields = { 
            "email": "email_address"
        }

If I could easily create a serializer field from a model field that would work as well. I always specify all my fields directly anyway

class UserSerializer(ModelSerializer):
    email = ModelSerializer.build_field(User.email_address)

    class Meta:
        model = User
        fields = ["name", "email"]

[ahosie]

I've smacked into this one today and the fix is actually pretty straightforward and django-esque.

Set a source attribute and stick to the regular field serializers wherever you can. Using ModelField should probably be an exception not the rule.

Given the posted example:

from django.db import models

class Connection(models.Model):
    date = models.DateTimeField(auto_now_add=True)
    user = organisation = models.ForeignKey(models.CASCADE)

Then a corresponding serializer that does what the OP wants would be:

from rest_framework import serializers

class OrganisationSerializer(serializers.HyperlinkedModelSerializer):
    creation_date = serializers.DateTimeField(source="date")

    class Meta:
        model = Connection
        fields = ["creation_date", "user"]