[Dbix-class] Optimistic locking

[Matt S Trout]

Dan Horne wrote:
> Hi
> 
> I'd like to implement a form of optimistic locking in one of my apps. Rather
> than handle this manually in the app itself, I'm hoping to reduce the coding
> overhead by incorporating the logic in a DBIC component. The basic steps
> are:
> 
> 1. Generate a pseudocolumn that contains a hash of the current row (or
> allrows if $rs->all). 
> 2. At some point in the future, a user will try to save the record via a
> webform. The overridden update method will query the original row and
> recompute the hash. If the two hashes don't match, an exception will be
> thrown.
> 
> So, my question is: Is there any way to create such a pseudocolumn that can
> be populated as a result of the values of the other columns?

Why do you need a "pseudocolumn" ?

It's just a perl object. Add an accessor ...