Re: Fundamental flaw in Model-Driven?

> I haven't had an opportunity to absorb your suggestion properly yet but
> thought I'd mention I agree with your line of thinking that the
> validation mechanism in particular needs to be improved. However, this
> is a general problem that also applies to rich clients; that is
> responsibility for rolling back changes to a model, and various patterns
> have developed over the years.  A temporary copy is a simple
> implementation, however within a JPA-environment automatically creating
> a clone is often infeasible or undesirable. For example, if it's
> attached to a session, this process may cause hydration of the entire
> object graph. Unless the framework is provided hints, it won't know what
> to safely/efficiently clone.
>
> Having the framework maintain dirty flags or proxy for the model also
> seems ineffective as the JPA provider performs the exact same task, only
> better.
>
> The option to write straight to the model (or DTO) and performing
> validation of the model (or DTO) is a distinguishing feature of Struts
> 2, but also the source of such complications. Anyway, I don't have a
> solution, but I do intend to start resolving the numerous validation
> issues in JIRA in the near future and this one is the list.