django rest framework

gistfile1.txt

I have the following two models: Blueprint and Workload.
The Blueprint model instance should have a collection of Workloads associated with it.
Initially, bot the Blueprint and Workload instances should be allowed to be created independently.
A complete typical scenario as follows:

1) a new Blueprint instance is created
2) a new Workload instance is created
3) the created Workload instance is added to the Blueprint's 'workloads' collection

The python REPL version is this:

blueprint = Blueprint(name="bluepint 1")
blueprint.save()
workload = Workload)name="workload 1")
workload.save()
blueprint.workloads.add(blueprint)
blueprint.save()

In my python client, I am able to create the instances of the Blueprint and Workload independently, and without issue.

My question is: what is the proper HTTP method and the corresponding URL syntax, to add a Workload to the Blueprint's 'workloads' collection.

Here is the models.py:

class Workload(models.Model):
    name = models.CharField(max_length=120, blank=True, default='')
    description = models.TextField()
    image = models.CharField(max_length=120, blank=True, default='')
    flavor = models.CharField(max_length=120, blank=True, default='')
    blueprint = models.ForeignKey('Blueprint', related_name='workloads', null=True)

    class Meta:
        ordering = ('name',)
        unique_together = ('blueprint', 'name')

    def __unicode__(self):
        return '%d: %s' % (self.name, self.description)


class Blueprint(models.Model):
    name = models.CharField(max_length=120, blank=True, default='')
    description = models.TextField()

    class Meta:
        ordering = ('name',)


And here is the serializers.py:

# region Workload Serializer
class WorkloadSerializer(serializers.Serializer):
    pk = serializers.IntegerField(read_only=True)
    name = serializers.CharField(required=False, allow_blank=True, max_length=120)
    description = serializers.CharField(style={'type': 'textarea'})
    image = serializers.CharField(required=False, allow_blank=True, max_length=120)
    flavor = serializers.CharField(required=False, allow_blank=True, max_length=120)


    def create(self, validated_data):
        """
        Create and return a new `Snippet` instance, given the validated data.
        """
        return Workload.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """
        Update and return an existing `Snippet` instance, given the validated data.
        """
        instance.name = validated_data.get('name', instance.name)
        instance.description = validated_data.get('description', instance.description)
        instance.image = validated_data.get('image', instance.image)
        instance.flavor = validated_data.get('flavor', instance.flavor)
        instance.save()
        return instance
# endregion


# region Blueprint Serializer
class BlueprintSerializer(serializers.ModelSerializer):
    workloads = serializers.StringRelatedField(many=True, required=False)
    pk = serializers.IntegerField(read_only=True)
    name = serializers.CharField(required=False, allow_blank=True, max_length=120)
    description = serializers.CharField(style={'type': 'textarea'})

    def create(self, validated_data):
        """
        Create and return a new `Snippet` instance, given the validated data.
        """
        return Blueprint.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """
        Update and return an existing `Snippet` instance, given the validated data.
        """
        instance.name = validated_data.get('name', instance.name)
        instance.description = validated_data.get('description', instance.description)
        instance.save()
        return instance

    class Meta:
        model = Blueprint
        fields = ('name', 'description', 'workloads')
# endregion