Fields of Nested serializers

Question

In my nested serializer i want to show only movie name and exclude the other fields

[
    {
        "id": 2,
        "watchlist": [
            {
                "id": 3,
                "platform": "Netflix",
                "title": "Martian",
                "storyline": "A lost astronaut of Mars survived",
                "average_rating": 4.1,
                "total_rating": 2,
                "active": true,
                "created": "2022-04-05T05:37:35.902464Z"
            },
            {
                "id": 4,
                "platform": "Netflix",
                "title": "Intersteller",
                "storyline": "Finding new home",
                "average_rating": 0.0,
                "total_rating": 0,
                "active": true,
                "created": "2022-04-06T04:52:04.665202Z"
            },
            {
                "id": 5,
                "platform": "Netflix",
                "title": "Shutter Island",
                "storyline": "Psycopath",
                "average_rating": 0.0,
                "total_rating": 0,
                "active": true,
                "created": "2022-04-06T04:52:51.626397Z"
            }
        ],
        "platform": "Netflix",
        "about": "streaming, series and many more",
        "website": "https://www.netflix.com"
    },
    
]

In the above data, "watchlist" is the nested serializer data i want to show only "title" and exclude all other data

I have included WatchListSerializer class as "nested" serializer in the StreamPlatformSerializer class. I want that on "title should be shown, rest other fields should be excluded from nested serializer part"

below is the code...

class WatchListSerializer(serializers.ModelSerializer):
    # reviews = ReviewSerializer(many=True, read_only=True)
    platform = serializers.CharField(source='platform.platform')
    class Meta:
        model = WatchList
        fields = '__all__'

    # def to_representation(self, value):
    #     return value.title


class StreamPlatformSerializer(serializers.ModelSerializer):
    watchlist = WatchListSerializer(many=True, read_only=True)
    # watchlist = serializers.CharField(source='watchlist.title')
    class Meta:
        model = StreamPlatform
        fields = '__all__'

after removing other fields it should look like this as below..

[
    {
        "id": 2,
        "watchlist": [
            {
              
                "title": "Martian"
            },
            {
                "title": "Intersteller",
                
            },
            {
                
                "title": "Shutter Island",
                
        ],
        "platform": "Netflix",
        "about": "streaming, series and many more",
        "website": "https://www.netflix.com"
    },
    
]

Answer 1

There may be two approaches for this thing First Approach:

class WatchListSerializer(serializers.ModelSerializer):
    # reviews = ReviewSerializer(many=True, read_only=True)
    class Meta:
        model = WatchList
        fields = ("title",)

    # def to_representation(self, value):
    #     return value.title


class StreamPlatformSerializer(serializers.ModelSerializer):
    watchlist = WatchListSerializer(many=True, read_only=True)
    # watchlist = serializers.CharField(source='watchlist.title')
    class Meta:
        model = StreamPlatform
        fields = '__all__'

With this approach the downside will be that WatchListSerializer can only be used in this serializer not as a standalone serializer.

For second approach I need to see your models. It would be like

class StreamPlatformSerializer(serializers.ModelSerializer):
    watchlist = serializers.SerializerMethodField("get_watchlist")
    class Meta:
        model = StreamPlatform
        fields = '__all__' # include watchlist as well
        
    def get_watchlist(self, obj):
        return obj.watchlist.all().values('title')

I like this approach personally.