Gotcha! Cheers.
2008/10/27 Jeremy Thomerson <[EMAIL PROTECTED]>
> Why is your property model not returning the String version for label
> anyway? It is generally bad form to rely on toString() for a display
> value.... So rather than returning Movie, do: new
> PropertyModel(ThingThatHoldsMovie, "movie.title") - wrap that in the model
> I
> showed earlier, and you have your solution.
>
> Otherwise, you could just override onComponentTagBody with:
> @Override
> protected void onComponentTagBody(final MarkupStream markupStream, final
> ComponentTag openTag)
> {
> Object obj = getDefaultModelObject();
> String val = obj == null ? "your string" : obj;
> replaceComponentTagBody(markupStream, openTag, val);
> }
>
>
> In other words, any of these options will work, but like you say - you
> probably shouldn't have a model that returns a Movie sometimes and a String
> other times. This is contrary to the "generified" contract.
>
> --
> Jeremy Thomerson
> http://www.wickettraining.com
>
>
> On Sun, Oct 26, 2008 at 8:22 PM, Antony Stubbs <[EMAIL PROTECTED]
> >wrote:
>
> > Hmm, generics soup...
> > How would this version work in the case where I would normally have a
> > domain
> > object resolving my model - e.g. Movie, and I don't want to make a
> 'default
> > Movie' of title "n/a"?
> >
> > Hmm, actually I think this high lights an error in my
> DefaultPropertyModel,
> > because if it's genereified with String, that's fine for when it's the
> > default string value, and it's fine for code which simply calls
> > getObject().toString (as label does), but if I had other code that called
> > getObject() and expected a String, as the compiler says it will return a
> > String, where in fact it will return a Movie.
> >
> > 2008/10/27 Jeremy Thomerson <[EMAIL PROTECTED]>
> >
> > > You might try something like this that could be used with any kind of
> > > model,
> > > including a property model:
> > >
> > > public class DefaultWhenNullModel<T> implements IModel<T> {
> > >
> > > private static final long serialVersionUID = 1L;
> > >
> > > private final IModel<T> mNestedModel;
> > > private final T mDefaultValue;
> > >
> > > public DefaultWhenNullModel(IModel<T> nestedModel, T defaultValue) {
> > > mNestedModel = nestedModel;
> > > mDefaultValue = defaultValue;
> > > }
> > >
> > > public T getObject() {
> > > T val = mNestedModel.getObject();
> > > return val == null ? mDefaultValue : val;
> > > }
> > >
> > > public void setObject(T object) {
> > > mNestedModel.setObject(object);
> > > }
> > >
> > > public void detach() {
> > > mNestedModel.detach();
> > > }
> > >
> > > }
> > >
> > > It could be used like: new DefaultWhenNullModel<String>(new
> > > PropertyModel<String>(object, "property"), "your message");
> > >
> > > Nesting models like this can get you some very effective reusable
> pieces
> > of
> > > code.
> > >
> > > --
> > > Jeremy Thomerson
> > > http://www.wickettraining.com
> > >
> > > On Sun, Oct 26, 2008 at 6:55 PM, Antony Stubbs <
> [EMAIL PROTECTED]
> > > >wrote:
> > >
> > > > Would something as minor as this be considered for the core?
> > > > I find it useful because I often want a component (in may case a
> Label
> > > > type)
> > > > to render a short message if the model is null e.g. "n/a" or "please
> > > select
> > > > a type of cheese". I first tried extending Label to do this, but hit
> a
> > > wall
> > > > because getDefaultModelObjectAsString is final (onComponentTagBody is
> > > > protected, but getDefaultModelObjectAsString returning "" is not the
> > same
> > > > as
> > > > null).
> > > > Let me know if there's a nicer way to achieve the same thing. class
> > > > DefaultPropertyModel<T> extends PropertyModel<T> { private T
> > > defaultModel;
> > > > public DefaultPropertyModel(Object modelObject, String expression, T
> > > > defaultObject) { super(modelObject, expression); this.defaultModel =
> > > > defaultObject; } @Override public T getObject() { T o =
> > > super.getObject();
> > > > if (o == null) return this.defaultModel; return o; } } --
> > > > ___________________________ http://stubbisms.wordpress.com/
> > > >
> > >
> >
> >
> >
> > --
> > ___________________________
> > http://stubbisms.wordpress.com/
> >
>
--
___________________________
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