Django tastypie: how to retrieve a list of child objects and attach that list to the 'choices' field atrribute

Question

I have a model class named Blueprint:

class Blueprint(models.Model):
    name = models.CharField(max_length=120)
    description = models.TextField()
    workloads = models.CharField(choices=WORKLOAD_CHOICES)

    class Meta:
        ordering = ["name", ]

This model has children named workloads.

Being totally new to both, django and tastypie, I have this question:

1) Where do I execute the logic, which retrieves the list of workloads, and populates the WORKLOAD_CHOICES: in the models.py (as part of the init) or in the api.py as part of def obj_get ?

P.S. Here is the api.py:

class BlueprintResource(ModelResource):
    def obj_create(self, bundle, request=None, **kwargs):
        return super(BlueprintResource, self).obj_create(bundle, request)

    def obj_update(self, bundle, request=None, **kwargs):

        blueprint = Blueprint.objects.get(id=kwargs.get("pk"))
        blueprint.description = bundle.data.get("description")
        blueprint.name = bundle.data.get("name")
        blueprint.workloads = bundle.data.get("workloads")
        blueprint.save()

        def obj_delete(self, bundle, **kwargs):

            return super(BlueprintResource, self).obj_delete(bundle)

    class Meta:
        queryset = Blueprint.objects.all()
        resource_name = 'blueprint'
        authorization=Authorization()

Answer 1

Have a look at build_bundle() and full_dehydrate(). I haven't tested this but maybe something like this would work.

from my_app.models import WORKLOAD_CHOICES

class BlueprintResource(ModelResource):

    def full_dehydrate(self, bundle, for_list=False):

         dic = dict([WORKLOAD_CHOICES])
         bundle.data['foo'] = self.build_bundle(data=dic)

         return super(BlueprintResource, self).full_dehydrate(bundle, for_list)