Haseeb Ahmad Haseeb Ahmad - 9 months ago 71
Ruby Question

Difference between after_create,after_save and after_commit in rail callbacks

Diffeerence between them which I know is that

is invoke when an object is created and updated and
fires on create, update and destroy.While after_create is only when creating an object

Is this the only differnce between them or there are another major differences?

Answer Source

You almost got it right. However there is one major difference between after_commit and after_create or after_save i.e.

In the case of after_create, this will always be before the call to save (or create) returns.

Rails wraps every save inside a transaction and the before/after create callbacks run inside that transaction (a consequence of this is that if an exception is raised in an after_create the save will be rolled back). With after_commit, your code doesn't run until after the outermost transaction was committed. This could be the transaction rails created or one created by you (for example if you wanted to make several changes inside a single transaction). Originally posted here

That also means, that if after_commit raises an exception, then the transaction won't be rolled back.