12 Sep
2009
12 Sep
'09
9:57 p.m.
Hi
Recently #kind was made mutable on MADescription. I think this is
great and set it on the containers of my model classes to my model
classes. This allows me to do the following:
aDescription kind new
which is really cool. The problem is that now I always get kind
validation errors. The cause is the following code in MADescription:
validateKind: anObject
"Validate ==anObject== to be of the right kind."
(anObject isKindOf: self kind)
ifFalse: [ MAKindError description: self signal: self kindErrorMessage ]
anObject would be an MACheckedMemento. self kind would previously
always answer Object so this test would always pass. Now however self
kind answers my model class and always fails.
Any ideas?
Cheers
Philippe
12 Sep
12 Sep
10:54 p.m.
Any ideas?
I think you should not use #kind to instantiate new objects, but add
your own property to hold the class you want to instantiate.
Cheers,
Lukas
--
Lukas Renggli
http://www.lukas-renggli.ch
13 Sep
13 Sep
10:29 a.m.
2009/9/12 Lukas Renggli <renggli(a)gmail.com>om>:
That doesn't solve the problem that kind validation is borken for containers.
Cheers
Philippe
Any ideas?
I think you should not use #kind to instantiate new objects, but add
your own property to hold the class you want to instantiate.
10:35 a.m.
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.
10:58 a.m.
2009/9/13 Lukas Renggli <renggli(a)gmail.com>om>:
#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.
Cheers
Philippe
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.
11:50 a.m.
2009/9/13 Philippe Marschall <philippe.marschall(a)gmail.com>om>:
2009/9/13 Lukas Renggli <renggli(a)gmail.com>om>:
#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.
Lukas
--
Lukas Renggli
http://www.lukas-renggli.ch
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.
12:02 p.m.
2009/9/13 Lukas Renggli <renggli(a)gmail.com>om>:
2009/9/13 Philippe Marschall
<philippe.marschall(a)gmail.com>om>:
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.
Cheers
Philippe
2009/9/13 Lukas Renggli
<renggli(a)gmail.com>om>:
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. > 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.
12:14 p.m.
2009/9/13 Philippe Marschall <philippe.marschall(a)gmail.com>om>:
2009/9/13 Lukas Renggli <renggli(a)gmail.com>om>:
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?
Lukas
--
Lukas Renggli
http://www.lukas-renggli.ch
2009/9/13 Philippe Marschall
<philippe.marschall(a)gmail.com>om>:
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 Lukas Renggli
<renggli(a)gmail.com>om>:
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. >> 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.
12:24 p.m.
2009/9/13 Lukas Renggli <renggli(a)gmail.com>om>:
2009/9/13 Philippe Marschall
<philippe.marschall(a)gmail.com>om>:
I though about this first too. However now I'm affraid of the possible
things it would break (debuggers, inspectors, ...). Considering that
something as simple as implementing #asString in Object can crash
VisualWorks this makes me very nervous. Maybe specifically handling
mementos or #magritteIsKindOf: are better.
Cheers
Philippe
2009/9/13 Lukas Renggli
<renggli(a)gmail.com>om>:
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? 2009/9/13 Philippe Marschall
<philippe.marschall(a)gmail.com>om>:
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 Lukas Renggli
<renggli(a)gmail.com>om>:
>>> 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.
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participants (2)
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Philippe Marschall