Would there be any objections to me removing the validators from the
fieldtype*.xml files?
-Adrian
--- On Sat, 6/26/10, David E Jones <d...@me.com> wrote:
> From: David E Jones <d...@me.com>
> Subject: Re: Discussion: Entity Engine Field Validators
> To: dev@ofbiz.apache.org
> Date: Saturday, June 26, 2010, 9:58 AM
>
> The validators are only used in the WebTools Entity Data
> Maintenance screens.
>
> They are intentionally not used in other parts of the
> project as validation is best in the logic layer, and not in
> the data layer (makes things far more reusable and
> flexible).
>
> I actually consider these to be a bad design from very
> early on in the project when the entity engine was one of
> the only tools in the framework, and IMO it would be better
> to remove them than to support them everywhere.
>
> -David
>
>
> On Jun 26, 2010, at 10:54 AM, Adrian Crum wrote:
>
> > The entity engine allows you to specify field
> validators in two places: in the fieldtypeXxx.xml files and
> in the the entity definition.
> >
> > The validators in the fieldtype files are not used as
> far as I can tell.
> >
> > The validators in the entity definitions require
> complicated client code to use them - they are not used
> automatically by the entity engine.
> >
> > The bottom line is, specifying a validator in either
> location does absolutely nothing. I don't know if this was
> designed this way or not.
> >
> > I have a design in mind that I think will be
> better...
> >
> > 1. Create a validator interface that can be used
> throughout the project:
> >
> > public interface Validator {
> > void isValid(Object obj;
> > }
> >
> > The isValid method throws an IllegalArgumentException
> if the object is not valid.
> >
> > 2. Set up a library of commonly used validators and
> put them in a Validator factory. Modify ModelField and
> ModelFieldType so they load validators from the factory.
> >
> > 3. Have ModelField and ModelFieldType implement
> Validator. Those classes delegate the isValid method call to
> their contained validators.
> >
> > 4. Modify GenericEntity.set method to call the
> ModelField's isValid method.
> >
> > The advantages to this approach are:
> >
> > 1. Validators are reusable. The same validators could
> be used on service parameters for example.
> > 2. Client code is shielded from validation details.
> Just call the isValid method.
> > 3. OFBiz users can implement custom Validator
> implementations and add them to the Validator factory.
> >
> > What do you think?
> >
> > -Adrian
> >
> >
> >
> >
>
>
