Instead of reflection in the cayenne core, have you considered
changing your entity template setters? Perhaps it could be provided
as an alternate WebObjects-esque template set.
public void setFoo(Foo newFool)
{
if (validateFoo(newFoo))
{
writeProperty("foo", newFoo);
}
}
public boolean validateFoo(Foo newFoo)
{
// do nothing by default
return true;
}
I don't remember the exact syntax for WebObjects or for Cayenne, but
the above example conveys the general idea.
On Tue, Mar 9, 2010 at 10:42 PM, Andrew Lindesay <ap..indesay.co.nz> wrote:
> Hello;
>
> As you may know, WebObjects/EOF has the protocol;
>
> NSValidation
>
> Specifically, this protocol implements the following two methods;
>
> Object validateTakeValueForKeyPath(Object value, String keyPath)
> Object validateValueForKey(Object value, String key)
>
> The effect is that when a client tries to write a property "foo", it will ultimately try to invoke;
>
> Object validateFoo(Object value) throws NSValidation.ValidationException
>
> ...before...
>
> setFoo(Object value)
>
> ...in order to either "repair" the value before assigning or to throw an exception. This is very handy from the user-interface perspective. For each attribute of an entity, this technique is also automatically used in the case of "validateForSave()" which means that aside from inter-attribute validation, per-attribute validations can be implemented just once.
>
> To provide this same behaviour to Cayenne, I would like to put forward the idea to implement something similar;
>
> validatedWriteProperty(ValidationResult vr, String propName, Object value)
> validatedWriteNestedProperty(ValidationResult vr, String propName, Object value)
>
> This would use (cached) reflection to look for a "validate" method and fire that before writing the property. For each attribute of a DataObject's entity, these methods would be fired from;
>
> void validateForSave(ValidationResult validationResult)
>
> Does this make sense in the context of Cayenne?
>
> Regards;
>
> ___
> Andrew Lindesay
> www.lindesay.co.nz
>
>
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