# How to determine if an object has just been created **URL:** \ **Category:** Rails\ **Created:** [May 19, 2006, 9:51am UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016 "2006-05-19T09:51:22Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![jonny](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/47e85d/32.png) [@jonny](https://www.ruby-forum.com/u/jonny)\ **Post date:** [May 19, 2006, 9:51am UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016/1 "2006-05-19T09:51:22Z")
Is there a built-in way to determine if a model object has just been created (ie. this object was the one that was originally persisted)? I can’t see it anywhere in the AR code, but thought I’d check. I want something like: p = Person.create p.original\_instance? # true Is this built-in or should I just patch AR? -Jonathan. ---
**Author:** ![jonny](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/47e85d/32.png) [@jonny](https://www.ruby-forum.com/u/jonny)\ **Post date:** [May 19, 2006, 10:07am UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016/2 "2006-05-19T10:07:20Z")
Jonathan V. wrote: > Is there a built-in way to determine if a model object has just been > created (ie. this object was the one that was originally persisted)? I > can’t see it anywhere in the AR code, but thought I’d check. I want > something like: > > p = Person.create > p.original\_instance? # true > > Is this built-in or should I just patch AR? > Not sure quite what you’re after, but does p.new\_record? do the trick? ---
**Author:** ![jonny](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/47e85d/32.png) [@jonny](https://www.ruby-forum.com/u/jonny)\ **Post date:** [May 19, 2006, 10:41am UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016/3 "2006-05-19T10:41:19Z")
On 5/19/06, Jonathan V. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > -Jonathan. > > * * * > > Rails mailing list > removed\_email\_address@domain.invalid > [http://lists.rubyonrails.org/mailman/listinfo/rails](http://lists.rubyonrails.org/mailman/listinfo/rails) I don’t think there’s a built-in way to do that…but it seems like it’d be pretty simple. def original\_instance? !new\_record? && created\_at == updated\_at end and just add created\_at and updated\_at fields to your model. Pat ---
**Author:** ![jonny](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/47e85d/32.png) [@jonny](https://www.ruby-forum.com/u/jonny)\ **Post date:** [May 19, 2006, 11:31am UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016/4 "2006-05-19T11:31:52Z")
> I don’t think there’s a built-in way to do that…but it seems like > it’d be pretty simple. From documentation: new\_record? Returns true if this object hasn’t been saved yet â?? that is, a record for the object doesn’t exist yet. Regards, Rimantas ---
**Author:** ![jonny](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/47e85d/32.png) [@jonny](https://www.ruby-forum.com/u/jonny)\ **Post date:** [May 19, 2006, 11:47am UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016/5 "2006-05-19T11:47:19Z")
On 5/19/06, Rimantas L. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > I don’t think there’s a built-in way to do that…but it seems like > > it’d be pretty simple. > > From documentation: > > new\_record? > Returns true if this object hasn’t been saved yet ? that is, a record > for the object doesn’t exist yet. > From the OP: > “this object was the one that was originally persisted” new\_record? tells you if the object hasn’t been saved. OP is asking how to tell if the record is the original one. My interpretation is basically that the object hasn’t been modified at all. The easiest way to do that (though perhaps not fool-proof) is to compare the updated\_at and created\_at fields. In fact, I used new\_record? in my code. Another possibility is acts\_as\_versioned, which may be more air-tight than my solution (though I don’t know if there are any problems with it, I just came up with it). Pat ---
**Author:** ![jonny](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/47e85d/32.png) [@jonny](https://www.ruby-forum.com/u/jonny)\ **Post date:** [May 19, 2006, 1:43pm UTC](https://www.ruby-forum.com/t/how-to-determine-if-an-object-has-just-been-created/61016/6 "2006-05-19T13:43:16Z")
The reason for doing this is to be able to send emails when certain models are created and/or changed. I realised just after I made the post that I should use AR callbacks (after\_create and after\_update) on the models, and possibly an observer. Thanks, -Jonathan.