mementos and kind validation on containers

> 2009/9/13 Lukas Renggli <[hidden email]>:
>>>> I think you should not use #kind to instantiate new objects, but add
>>>> your own property to hold the class you want to instantiate.
>>>
>>> That doesn't solve the problem that kind validation is borken for containers.
>>
>> #kind is used for validation and that should remain like this. The
>> default for containers is Object, so it is a no-op that passes the
>> validation for all objects.
>
> Not if you set kind on a container. And the check is not a no-op at
> all. It checks the class of the memento against the kind which makes
> no sense at all.

> 2009/9/13 Philippe Marschall <[hidden email]>:
>> 2009/9/13 Lukas Renggli <[hidden email]>:
>>>>> I think you should not use #kind to instantiate new objects, but add
>>>>> your own property to hold the class you want to instantiate.
>>>>
>>>> That doesn't solve the problem that kind validation is borken for containers.
>>>
>>> #kind is used for validation and that should remain like this. The
>>> default for containers is Object, so it is a no-op that passes the
>>> validation for all objects.
>>
>> Not if you set kind on a container. And the check is not a no-op at
>> all. It checks the class of the memento against the kind which makes
>> no sense at all.
>
> Of course, for what it is designed for it makes perfectly sense.
>
> As I already said several times, forget about #kind, create your own
> property that is not used for validation and do with it whatever you
> want.

> 2009/9/13 Lukas Renggli <[hidden email]>:
>> 2009/9/13 Philippe Marschall <[hidden email]>:
>>> 2009/9/13 Lukas Renggli <[hidden email]>:
>>>>>> I think you should not use #kind to instantiate new objects, but add
>>>>>> your own property to hold the class you want to instantiate.
>>>>>
>>>>> That doesn't solve the problem that kind validation is borken for containers.
>>>>
>>>> #kind is used for validation and that should remain like this. The
>>>> default for containers is Object, so it is a no-op that passes the
>>>> validation for all objects.
>>>
>>> Not if you set kind on a container. And the check is not a no-op at
>>> all. It checks the class of the memento against the kind which makes
>>> no sense at all.
>>
>> Of course, for what it is designed for it makes perfectly sense.
>>
>> As I already said several times, forget about #kind, create your own
>> property that is not used for validation and do with it whatever you
>> want.
>
> But why is #kind mutable on MADescription when setting it results in
> failing validation? This is very bad API design. At least it should be
> pushed down to MAElement description.

> 2009/9/13 Philippe Marschall <[hidden email]>:
>> 2009/9/13 Lukas Renggli <[hidden email]>:
>>> 2009/9/13 Philippe Marschall <[hidden email]>:
>>>> 2009/9/13 Lukas Renggli <[hidden email]>:
>>>>>>> I think you should not use #kind to instantiate new objects, but add
>>>>>>> your own property to hold the class you want to instantiate.
>>>>>>
>>>>>> That doesn't solve the problem that kind validation is borken for containers.
>>>>>
>>>>> #kind is used for validation and that should remain like this. The
>>>>> default for containers is Object, so it is a no-op that passes the
>>>>> validation for all objects.
>>>>
>>>> Not if you set kind on a container. And the check is not a no-op at
>>>> all. It checks the class of the memento against the kind which makes
>>>> no sense at all.
>>>
>>> Of course, for what it is designed for it makes perfectly sense.
>>>
>>> As I already said several times, forget about #kind, create your own
>>> property that is not used for validation and do with it whatever you
>>> want.
>>
>> But why is #kind mutable on MADescription when setting it results in
>> failing validation? This is very bad API design. At least it should be
>> pushed down to MAElement description.
>
> Indeed, you are right, but that has nothing to do with the initial problem.
>
> Maybe the MAMemento should rather implement #isKindOf: to dispatch to
> the delegate?