How to use custom serializers fields in my HyeprlinkedModelSerializer

Question

I need to store bitmap representation of an image in my code, so I did this in my model

logo = models.BinaryField(blank=True, null=True)

now Django-rest doesn't have a serializer field for BinaryField. If I create my own serializer field for this, how would I be able to use it in my code ? For example, if I create something like

class MyBinaryField(serializers.Field):
    def to_representation(self, obj):
        return base64.b64decode(obj)
    def to_internal_value(self, data):
        return base64.encodestring(data)

How can I plug this mapping of models.BinaryField and MyBinaryField in my serializer. I know there is a default serializer_field_mapping map available and I can override it, but I want to use existing serializer_field_mapping as well. How can I insert my new entry into existing serializer_field_mapping or declare new values in current map ?

score 4 · Answer 1 · answered Oct 07 '17 at 12:59

Just make a copy of serializer_field_mapping from the base class of your serializer and update it with new "model field - serializer" field pair. For example if you use ModelSerializer subclass then:

from rest_framework import serializers
class MySerializer(serializers.ModelSerializer):
    serializer_field_mapping = (
        serializers.ModelSerializer.serializer_field_mapping.copy()
    )
    serializer_field_mapping[models.BinaryField] = MyBinaryField

score 0 · Answer 2 · answered Jul 25 '15 at 09:18

One way to do this,

class MySerializer(serializers.Serializer):
    logo = MyBinaryField()

However, I suppose you are asking about overriding model serializer field then you could use the following,

class AccountSerializer(serializers.ModelSerializer):
    logo = MyBinaryField(read_only=True)

    class Meta:
        model = Account

Reference from Docs

How to use custom serializers fields in my HyeprlinkedModelSerializer

2 Answers2

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