DRF use nested serializer to create key object instead of array - python-3.x

Question

Context
Say we take this example from the DRF relations guide.
# models.py
class Album(models.Model):
album_name = models.CharField(max_length=100)
artist = models.CharField(max_length=100)
class Track(models.Model):
album = models.ForeignKey(Album, related_name='tracks', on_delete=models.CASCADE)
order = models.IntegerField()
title = models.CharField(max_length=100)
duration = models.IntegerField()
class Meta:
unique_together = ('album', 'order')
ordering = ['order']
def __str__(self):
return '%d: %s' % (self.order, self.title)
Using a serializer will get us this output
class AlbumSerializer(serializers.ModelSerializer):
tracks = serializers.StringRelatedField(many=True)
class Meta:
model = Album
fields = ('album_name', 'artist', 'tracks')
Will get us this output:
{
'album_name': 'Things We Lost In The Fire',
'artist': 'Low',
'tracks': [
'1: Sunflower',
'2: Whitetail',
'3: Dinosaur Act',
...
]
}
Question
How can i use the serializer to get the output like this:
{
'album_name': 'Things We Lost In The Fire',
'artist': 'Low',
'tracks': {
1: {order: 1, title: 'Sunflower'},
2: {order:2, title: 'Whitetail'},
3: {order:3, title: 'Dinosaur Act'},
...
}
}
This way we have an object with tracks instead of a numeric array. So i can do this.props.album.tracks[2].title this instead of this.props.album.tracks.find(track => track.order == 2}).title in javascript.
``I have an use case in where this seems to be more convenient in Reactjs.
What i have tried
I thought about overriding the to_representation method. But i see that this will get me an recursive loop.
class TrackSerializer(serializers.ModelSerializer):
def to_representation(self, instance):
print(self)
return '%s: { %s }' % (instance.order, self.to_representation(instance))
class Meta:
fields = '__all__'
model = Track
Furthermore i have searched and read the docs pretty well. But didn't find any solution for what i think should be a pretty logical solution to have out of the box. Making me think that i am wrong and missing something.
Thanks in advance.

Answer 1

Define a new TrackSerializer and use it in AlbumSerializer class as,
class TrackSerializer(serializers.ModelSerializer):
class Meta:
model = Track
fields = ('id', 'order', 'title')
class AlbumSerializer(serializers.ModelSerializer):
tracks = TrackSerializer(many=True)
class Meta:
model = Album
fields = ('album_name', 'artist', 'tracks')
def to_representation(self, instance):
representation = super().to_representation(instance)
representation['tracks'] = {track['id']: track for track in representation['tracks']}
return representation