Proposal: auto_now and auto_now_add options for DateTimeField

[mongoengine]

Proposal: auto_now and auto_now_add options for DateTimeField

[beyondliu]

So is this supported now? In which version? Thanks!

[bagerard]

Just to clarify, auto_now and auto_now_add don't exist in mongoengine

[rohitkhatri]

@hygull In which version, does it work? I am using 0.13.0 and It's not working in my case.

[rozza]

Well I'd suggest using signals, but it all depends on how you update your documents. Doing a save in pymongo will overwrite a document and isn't atomic. We do some handling of that, to make it atomic but there is a big cost in performance involved.

You can set a default which covers auto_now_add but auto_now is tricker to implement as it may be a mass update and arguably should be left to the application developer to implement.

[lig]

Well, I've just noticed once more callable defaults and see default=lambda: datetime.utcnow() variant. But may be it will be useful to have this out of the box.

And yes, I understand that implementing auto_now is a kind of scary task:)

Also, I think that documenting design principles for auto_now and auto_now_add and the reasons why there shouldn't be auto_now out of the box will be very useful.

[rozza]

I dont think its a scary task - should be relatively trivial, its just we'd have to hook into every save (easy) and inject into every update call - maybe unexpected for the user.

I'll schedule for post 0.7 - but it might make 0.7

[lig]

Thank you very much!

Now I may try to contribute some code on this task. Not promising that I will though.

[rozza]

Having to bump to 0.8 as PY3 support came early!

[csabaszilveszter]

damn... how do I deactivate this :))

[hygull]

Look at the following code snippet, it will clarify.

class Post(models.Model):
     title = models.CharField(max_length=50, blank=False)
     description = models.TextField()
     pic = models.URLField(max_length=1000) #default max_length is 200
     created = models.DateTimeField(auto_now_add=True, auto_now=False)
     updated = models.DateTimeField(auto_now_add=False, auto_now=True)
     posted_by = models.ForeignKey(User, on_delete=models.CASCADE) # "User" => won't work

     def __unicode__(self):
           return self.title

[metadeng]

@hygull it's seem like that model by django,is really supported in mongo too?

[hygull]

@lvtuben Yes it supports. We can check this at Using MongoDB as your primary Django database.

[oussjarrousse]

Why unsure of this feature if it is already implemented?
And why is this issue still open?

[hygull]

Can you please check https://staltz.com/djangoconfi-mongoengine/#/9

[hygull]

@hygull In which version, does it work? I am using 0.13.0 and It's not working in my case.

Can you please check https://staltz.com/djangoconfi-mongoengine/#/9

[rafaelreuber]

This is really very useful!

[oussjarrousse]

This is very useful. I wonder why wouldn't it be part of the package... I am forced to overload the save() function for every model class to add it.

[leonballoniMakes]

This is probably not going to be added since passed 11 years already.