Actuellement, cela n'est pas pris en charge directement car MongoEngine ne prend en charge que la syntaxe json étendue de mongodb.
Tout ce que mongoengine fait sous les couvertures est d'utiliser json_utils de pymongo pour vider les données. Il n'y a aucune raison pour que vous ne puissiez pas l'utiliser explicitement, par exemple :
from bson import json_util
class Inbox(db.Document):
from_user = db.ReferenceField(User, required=True)
subject = db.StringField(max_length=255, required=True)
created_at = db.DateTimeField(default=datetime.now)
messages = db.ListField(db.EmbeddedDocumentField(Message))
def to_json(self):
data = self.to_mongo() // get the pymongo representation of the document
data["from_user"] = {"User": {"username": self.from_user.username}}
return json_util.dumps(data)
User.drop_collection()
...
Inbox.drop_collection()
ross = User(username="Ross").save()
Inbox(from_user=ross, subject="Mongoengine should make json easier").save()
doc = Inbox.objects.only('from_user', 'subject', 'created_at').get()
print doc.to_json()
{"_id": {"$oid": "538c3d71c3d384172fe35393"},
"from_user": {"User": {"username": "Ross"}},
"subject": "Mongoengine should make json easier",
"created_at": {"$date": 1401703297198}, "messages": []}
Mise à jour
Exemple avec un jeu de requêtes personnalisé :
from bson import json_util
class CustomQuerySet(QuerySet):
def to_json(self):
return "[%s]" % (",".join([doc.to_json() for doc in self]))
class Inbox(Document):
from_user = ReferenceField(User, required=True)
subject = StringField(max_length=255, required=True)
created_at = DateTimeField(default=datetime.now)
messages = ListField(EmbeddedDocumentField(Message))
meta = {'queryset_class': CustomQuerySet}
def to_json(self):
data = self.to_mongo()
data["from_user"] = {"User": {"username": self.from_user.username}}
return json_util.dumps(data)
...
ipdb> Inbox.objects.only('from_user', 'subject', 'created_at').to_json()
'[{"_id": {"$oid": "538d84cbc3d3843eeeb5dbbe"},
"from_user": {"User": {"username": "Ross"}},
"subject": "Mongoengine should make json easier",
"created_at": {"$date": 1401787099246}, "messages": []}]'
