Serialize MongoDB Data with Django REST Framework

Install Django MongoDB Extensions.

Run the following command to install Django MongoDB Extensions with the rest_framework dependency:

pip install "django-mongodb-extensions[rest_framework]"

Update your installed apps.

Navigate to your project's settings.py file. Then, add "django_mongodb_extensions" and "rest_framework" to the INSTALLED_APPS setting, as shown in the following example:

INSTALLED_APPS = [
    'django_mongodb_extensions',
    'rest_framework',
    # ... your other apps
]

Set up your files.

In the Get Started tutorial, you created a models.py file that includes the following code:

from django.db import models
from django.conf import settings
from django_mongodb_backend.fields import EmbeddedModelField, ArrayField
from django_mongodb_backend.models import EmbeddedModel
class Award(EmbeddedModel):
    wins = models.IntegerField(default=0)
    nominations = models.IntegerField(default=0)
    text = models.CharField(max_length=100)
class Movie(models.Model):
    title = models.CharField(max_length=200)
    plot = models.TextField(blank=True)
    runtime = models.IntegerField(default=0)
    released = models.DateTimeField("release date", null=True, blank=True)
    awards = EmbeddedModelField(Award, null=True, blank=True)
    genres = ArrayField(models.CharField(max_length=100), null=True, blank=True)
    class Meta:
        db_table = "movies"
        managed = False
    def __str__(self):
        return self.title
class Viewer(models.Model):
    name = models.CharField(max_length=100)
    email = models.CharField(max_length=200)
    class Meta:
        db_table = "users"
        managed = False
    def __str__(self):
        return self.name

Ensure that your app directory contains this file. Then, create a serializers.py file in the same directory as your models.py file.

Serialize a model.

To serialize a model that uses ObjectIdAutoField, define a serializer that extends MongoModelSerializer in your serializers.py file. The following example defines a serializer for the Viewer model:

from django_mongodb_extensions.rest_framework import MongoModelSerializer
from .models import Viewer
class ViewerSerializer(MongoModelSerializer):
    class Meta:
        model = Viewer
        fields = "__all__"

Serialize an embedded model.

To serialize a field that stores an embedded model, define a serializer that extends EmbeddedModelSerializer for the embedded model, then reference it from the parent model's serializer.

To serialize the Movie model and its embedded Award model, update your serializers.py file to resemble the following:

from django_mongodb_extensions.rest_framework import (
    MongoModelSerializer,
    EmbeddedModelSerializer,
)
from .models import (
    Viewer,
    Award,
    Movie,
)
class ViewerSerializer(MongoModelSerializer):
    class Meta:
        model = Viewer
        fields = "__all__"
class AwardSerializer(EmbeddedModelSerializer):
    class Meta:
        model = Award
        fields = "__all__"
class MovieSerializer(MongoModelSerializer):
    awards = AwardSerializer()
    class Meta:
        model = Movie
        fields = "__all__"

View the serialized output of a model.

After you define a serializer, you can use it to convert a model instance into a dictionary of primitive data types that Django REST Framework can render as JSON.

Start a Python shell by running the following command:

python manage.py shell

Then, run the following code to query the sample_mflix.users collection for a viewer and serialize the result:

from sample_mflix.models import Viewer
from sample_mflix.serializers import ViewerSerializer
viewer = Viewer.objects.get(email="jason_momoa@gameofthron.es")
serializer = ViewerSerializer(viewer)
serializer.data

The data attribute contains the serialized representation of the viewer, which resembles the following output:

{'id': '...', 'name': 'Khal Drogo', 'email': 'jason_momoa@gameofthron.es'}

View the serialized output of an embedded model.

When you serialize a model that contains an embedded model, the serializer nests the embedded model's fields in the output.

From your Python shell, run the following code to query the sample_mflix.movies collection for a movie and serialize the result:

from sample_mflix.models import Movie
from sample_mflix.serializers import MovieSerializer
movie = Movie.objects.first()
serializer = MovieSerializer(movie)
serializer.data

The serialized output nests the awards embedded model inside the movie, which resembles the following:

{'id': '...',
 'title': 'The Great Train Robbery',
 'plot': 'A group of bandits stage a brazen train hold-up...',
 'runtime': 11,
 'released': '1903-12-01T00:00:00Z',
 'awards': {'wins': 1, 'nominations': 0, 'text': '1 win.'},
 'genres': ['Short', 'Western']}