Hi,
In this particular code I think the "problem" is PropertyModel, since
it brings the type unsafety.
Another solution is to make Component<T>, this way we can remove
#setDefaultModel() and have #setModel(IModel<T>) only and such
problems will go away.
But as discussed in early Wicket 1.4 days this will lead to more
typing. With Java 7 diamonds it is half the typing though.
For now you can use GenericPanel, GenericPage and all FormComponent.
On Thu, Sep 27, 2012 at 10:41 AM, Michael Mosmann <mich...@mosmann.de> wrote:
> Am 27.09.2012 09:01, schrieb Martin Grigorov:
> Hi,
>
> I think, there is a little difference in using setDefaultModel and
> setDefaultModelObject .. the first one sets a new model instance, the second
> only change the value in the existing model. Some pseudo-code:
>
> class APanel extends Panel {
> APanel(String id,IModel<Some> model) {
> super(id,model);
>
> add(new Label("name",new PropertyModel(getDefaultModel(),"name"));
> }
> }
>
> If you replace the value in model, everything is fine and works as expected.
> If you call setDefaultModel you might think, that everything is fine, but
> its not. A child component does not use getParent().getDefaultModel() to get
> these changes. I saw a lot of code like this, which leads to trouble, if you
> change the model and not the value.
>
> If there is no benefit in using setDefaultModel over setDefaultModelObject i
> would like to remove this method. This could prevent many "you might not got
> the full picture how to use wicket the right way" errors.
>
> Michael
>
>
>> Hi,
>>
>> Most of the time it is recommended to use a dynamic model, so there is
>> no reason to replace the component's model.
>> Component#setDefaultModel() gives you semi-dynamic nature - you can
>> replace the model completely with a new one. Same with
>> #setDefaultModelObject().
>>
>> What is the problem you face with it ?
>>
>> On Thu, Sep 27, 2012 at 9:57 AM, Michael Mosmann <mich...@mosmann.de>
>> wrote:
>>>
>>> Hi,
>>>
>>> is there any usefull application of Component.setDefaultModel(...)? IMHO
>>> this Method is the cause for much trouble without any benefit. But maybe
>>> i
>>> did not understand when someone should replace a component model...
>>>
>>> thanks
>>> Michael
>>
>>
>>
>
--
Martin Grigorov
jWeekend
Training, Consulting, Development
http://jWeekend.com
