How do relationships work on the mongoengine?

I'm new in mongoengine and I'm trying to relate two documments.

class Actor(Document):
    name = StringField(required=True, unique=True)
    movies = ListField()

class Movie(Document):
    title = StringField(required=True, unique=True)
    release_date = DateField()
    director = StringField()
    cast = ListField(ReferenceField(Actor))

I'd like to list the actors and have the movies appear. Or list the movies and the actors would appear related.

In my mind, I think of something like this:

class Actor(Resource):
    def get_actors(self) -> Response:
        for actor in Actor.objects.all():
            movies = Movie.objects(actors=actor)
            [...]
        return Response(planets, mimetype='application/json', status=200)

Is this a valid path, or is my head in Postgres and Mongo different? Any ideas?

Solution

In mongoengine, if you use ReferenceField, this will auto queryset to Actor. So you only need create a function to return a dict value.

class Actor(Document):
    name = StringField(required=True, unique=True)
    movies = ListField()

    def as_dict(self):
        return {
            "id": str(self.pk),
            "name": self.name,
            "movies": self.movies
        }

class Movie(Document):
    title = StringField(required=True, unique=True)
    release_date = DateField()
    director = StringField()
    cast = ListField(ReferenceField(Actor))
    
    def as_dict(self):
        return {
            "id": str(self.pk),
            "title": self.title,
            "release_date": self.release_date.isoformat(),
            "director": self.director,
            "cast": [i_cast.as_dict() for i_cast in self.cast]
        }

In API, you only call ac_dict after query to return data

def get_actors(self) -> Response:
    actors = Actor.objects.all()
    return Response([actor.as_dict() for actor in actors], mimetype='application/json', status=200)