django-rest ModelSerializer select fields to display in nested relationship

Question

I'm going to reference the django-rest-framework API example on this. Lets say we have two serializers defined as below.

class TrackSerializer(serializers.ModelSerializer):
    class Meta:
        model = Track
        fields = ['order', 'title', 'duration']

class AlbumSerializer(serializers.ModelSerializer):
    tracks = TrackSerializer(many=True, read_only=True)

    class Meta:
        model = Album
        fields = ['album_name', 'artist', 'tracks']

Now if i do a GET request and retrieve an Album instance, it will return me a response with a list of Track instances inside it where each instance contains all the fields of Track. Is there a way to return only a selected subset of the fields in the Track model? For example to only return the title and duration field to the client but not the 'order' field.

Answer 1

You can make a specific TrackSerializer for your Album, like:

class TrackSerializer(serializers.ModelSerializer):
    class Meta:
        model = Track
        fields = ['order', 'title', 'duration']

class TrackForAlbumSerializer(serializers.ModelSerializer):
    class Meta:
        model = Track
        fields = ['title', 'duration']

class AlbumSerializer(serializers.ModelSerializer):
    tracks = TrackForAlbumSerializer(many=True, read_only=True)

    class Meta:
        model = Album
        fields = ['album_name', 'artist', 'tracks']

You do not have to define a single serializer per model, you can define multiple serializers you each use for a dedicated task.