JavaFX Form Validation

[Werner Lehmann]

Hi Will,

On 12.06.2012 17:50, Will Hoover wrote:
> Although, IMHO, the use of validation that doesn't pertain to domain
> models is more of an exception to the rule versus the rule itself...

I suppose most people tend to think that other usecases are the special
cases while the own usecase is the common one. There is probably no way
to know for sure what the exception is and what it is not. In the end it
makes sense to have a framework with as few limitations as possible.

Your suggestion assumes that a domain bean backs most UIs (at least when
validation is required). I don't think that is true, and I don't like to
create a domain bean for the sake of validation.

Furthermore, not every domain bean property translates to exactly one
control. And typically, domain beans do not have JavaFX style properties.

> The problem with this approach is that it's very redundant. If you
> use the same entity/domain model fields in multiple controls (which
> happens more frequently than one would think- different forms) then
> the developer is left with the responsibility of ensuring the
> consistency of the validations across different UI controls.

Redundancy is bad but: if your validation patterns etc can be discovered
automatically (e.g. with your pattern annotation) it should be possible
to connect your validation with whatever JavaFX validation we will end
up with. Sounds like a form of the mediator pattern. Surely this can be
made in a generic way.

Rgds
Werner