How do I include related model fields using Django Rest Framework

Question

Let's say that we have the following model:

class Classroom(models.Model):
    room_number = [....]

class Teacher(models.Model):
    name = [...]
    tenure = [...]
    classroom = models.ForeignKey(Classroom)

Let's say that instead of getting a result like this per the ManyRelatedPrimaryKeyField function:

{
    "room_number": "42", 
    "teachers": [
        27, 
        24, 
        7
    ]
},

have it return something that includes the full related model representation like:

{
    "room_number": "42", 
    "teachers": [
        {
           'id':'27,
           'name':'John',
           'tenure':True
        }, 
        {
           'id':'24,
           'name':'Sally',
           'tenure':False
        }, 
    ]
},

Is this possible? If so, how?

Answer 1

Hello @kartik,

The simplest way is to use the depth argument.

class ClassroomSerializer(serializers.ModelSerializer):
    class Meta:
        model = Classroom
        depth = 1

However, that will only include relationships for forward relationships, which in this case isn't quite what you need, since the teachers field is a reverse relationship.

If you've got more complex requirements you can nest serializers, eg.

class TeacherSerializer(serializers.ModelSerializer):
    class Meta:
        model = Teacher
        fields = ('id', 'name', 'tenure')

class ClassroomSerializer(serializers.ModelSerializer):
    teachers = TeacherSerializer(source='teacher_set')

    class Meta:
        model = Classroom

Note that we use the source argument on the serializer field to specify the attribute to use as the source of the field. We could drop the source argument by instead making sure the teachers attribute exists by using the related_name option on your Teacher model, ie. classroom = models.ForeignKey.

Hope this helps!!

Thank you!!