CODEWITHSUNDEEP
pythonmongodbmongoengine
gaggina
gaggina

Reputation: 5425

issue in mongoengine: ReferenceFields will default to using ObjectId

Following this official tutorial I've coded this:

#! /usr/bin/env python

from mongoengine import *

connect('tumbleblog')


class User(Document):
  email = StringField(required=True)
  first_name = StringField(max_length=50)
  last_name = StringField(max_length=50)

class Comment(EmbeddedDocument):
  content = StringField()
  name = StringField(max_length=120)

class Post(Document):
  title = StringField(max_length=120, required=True)
  author = ReferenceField(User, reverse_delete_rule=CASCADE)
  tags = ListField(StringField(max_length=30))
  comments = ListField(EmbeddedDocumentField(Comment))

class TextPost(Post):
  content = StringField()

class ImagePost(Post):
  image_path = StringField()

class LinkPost(Post):
  link_url = StringField()


john = User(email="[email protected]",first_name='john', last_name='doe')
john.save()

But I don't know why when trying to run it it says:

/Library/Python/2.7/site-packages/mongoengine/fields.py:736: FutureWarning: ReferenceFields will default to using ObjectId  strings in 0.8, set DBRef=True if this isn't desired
  warnings.warn(msg, FutureWarning)
/Library/Python/2.7/site-packages/mongoengine/base.py:589: FutureWarning: TextPost uses inheritance, the default for allow_inheritance is changing to off by default. Please add it to the document meta.
  FutureWarning
/Library/Python/2.7/site-packages/mongoengine/base.py:589: FutureWarning: ImagePost uses inheritance, the default for allow_inheritance is changing to off by default. Please add it to the document meta.
  FutureWarning
/Library/Python/2.7/site-packages/mongoengine/base.py:589: FutureWarning: LinkPost uses inheritance, the default for allow_inheritance is changing to off by default. Please add it to the document meta.
  FutureWarning
[Finished in 0.2s]

Where I went wrong? I've followed the official tutorial..Did I miss something?

PS Mongodb is up and running

Upvotes: 1

Views: 1833

Answers (3)

Ross
Ross

Reputation: 18111

The future warning is there to alert you to changes in future versions of MongoEngine that will need addressing before you upgrade.

The warning is:

ReferenceFields will default to using ObjectId strings in 0.8, set DBRef=True if this isn't desired

What that means is - if you dont want to change and migrate your data you should change the definition to:

ReferenceField(User, dbref=False)  # Uses the original way of storing dbrefs
ReferenceField(User, dbref=True)   # Uses a simpler way of storing dbrefs

Upvotes: 3

ekini
ekini

Reputation: 100

Well, if you don't like that warnings, you can make Post to look like:

class Post(Document):
    meta = {'allow_inheritance': True}
    ...
    author = ReferenceField(User, reverse_delete_rule=CASCADE, dbref=False)
    ...

See http://mongoengine-odm.readthedocs.org/en/latest/upgrade.html and https://github.com/hmarr/mongoengine/issues/437 for more info.

Upvotes: 1

Petri
Petri

Reputation: 5016

Your code is using Comment before it is defined. Order matters in Python.

See for example https://stackoverflow.com/a/2985085/1256394.

Upvotes: 1

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