This alas does not work:(
First I am using wicket 7.2.0 and the getModelObject does not exist so I
finally made:
@Override
protected void onComponentTag(ComponentTag tag) {
add(new AttributeAppender("class", " number"));
if(getDefaultModel().getObject() instanceof Number){
Number number = (Number) getDefaultModelObject();
if(number.doubleValue()<0.0)
add(new AttributeAppender("class", " negative"));
}
}
This however gives the following exception:
org.apache.wicket.WicketRuntimeException: Cannot modify component
hierarchy after render phase has started (page version cant change
then anymore)
at org.apache.wicket.Component.checkHierarchyChange(Component.java:3623)
at org.apache.wicket.Component.addStateChange(Component.java:3538)
at org.apache.wicket.Behaviors.add(Behaviors.java:55)
at org.apache.wicket.Component.add(Component.java:4559)
at
nl.codetribe.budget.web.common.MoneyLabel.onComponentTag(MoneyLabel.java:36)
at org.apache.wicket.Component.internalRenderComponent(Component.java:2521)
On Fri, Apr 1, 2016 at 3:11 PM Tobias Soloschenko
tobiassolosche...@googlemail.com
<http://mailto:tobiassolosche...@googlemail.com> wrote:
Cool - thanks!
>
> kind regards
>
> Tobias
>
> > Am 01.04.2016 um 14:56 schrieb Martin Grigorov <mgrigo...@apache.org>:
> >
> > I've added an example with
> >
> https://github.com/apache/wicket/commit/2417322673238d57a794c237e84dd5dacf890804
> >
> > I think we should explain that those are just convenience. It is better
> to
> > use the "old way" one cares about memory usage. I'll add it soon.
> >
> > Martin Grigorov
> > Wicket Training and Consulting
> > https://twitter.com/mtgrigorov
> >
> > On Fri, Apr 1, 2016 at 2:48 PM, Tobias Soloschenko <
> > tobiassolosche...@googlemail.com> wrote:
> >
> >> Hi,
> >>
> >> would be great to see some information how to use lambda models in the
> >> user guide.
> >>
> >> kind regards
> >>
> >> Tobias
> >>
> >>>> Am 01.04.2016 um 13:57 schrieb Martin Grigorov <mgrigo...@apache.org
> >:
> >>>>
> >>>> On Fri, Apr 1, 2016 at 12:45 AM, Sven Meier <s...@meiers.net> wrote:
> >>>>
> >>>> Hi,
> >>>>
> >>>> yeah, of course this is right:
> >>>>
> >>>> protected void onComponentTag(final ComponentTag tag) {
> >>>>
> >>>> if (getModelObject().doubleValue() < 0.0) {
> >>>> tag.put("class", " negative");
> >>>> }
> >>>> }
> >>>>
> >>>> Otherwise you'll end up with one additional behavior for each render -
> >>>> stupid copy-paste error :/.
> >>>>
> >>>> BTW this might be an additional candidate for the new Wicket 8
> lambdas:
> >>>>
> >>>> label.add(onTag(tag -> if (getModelObject().doubleValue() < 0.0)
> >>>> tag.put("class", "negative") ));
> >>>
> >>> +1
> >>>
> >>
> >> +1
> >>
> >>>
> >>>>
> >>>> Sven
> >>>>
> >>>>
> >>>>
> >>>>> On 31.03.2016 21:16, Martin Grigorov wrote:
> >>>>>
> >>>>> Hi,
> >>>>>
> >>>>> On Thu, Mar 31, 2016 at 4:29 PM, Sven Meier <s...@meiers.net> wrote:
> >>>>>
> >>>>> Hi,
> >>>>>>
> >>>>>> you can access a component's model with #getDefaultModel() or - if
> it
> >> is
> >>>>>> a
> >>>>>> generic component - with #getModel().
> >>>>>>
> >>>>>> To properly 'bind' to a model you should delay invocation of
> >> #getObject()
> >>>>>> as late as possible, so better overwrite #onComponentTag():
> >>>>>>
> >>>>>> protected void onComponentTag(final ComponentTag tag) {
> >>>>>>
> >>>>>> if (getModelObject().doubleValue() < 0.0) {
> >>>>>> add(new AttributeAppender("class", " negative"));
> >>>>>>
> >>>>>> Since you are in #onComponentTag() there is no reason to add a
> >> Behavior.
> >>>>> Just use the tag: tag.append("class", "negative", " ");
> >>>>>
> >>>>>
> >>>>> }
> >>>>>> }
> >>>>>>
> >>>>>>
> >>>>>> Have fun
> >>>>>> Sven
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> On 31.03.2016 16:06, Ron Smits wrote:
> >>>>>>
> >>>>>> I have searched but I dont find a clear way of getting the model
> when
> >> one
> >>>>>>> is creating a custom component:
> >>>>>>>
> >>>>>>>
> >>>>>>> public MoneyLabel(String id) {
> >>>>>>> super(id);
> >>>>>>> add(new AttributeAppender("class", " number"));
> >>>>>>> }
> >>>>>>>
> >>>>>>> It sounds like you always need the model.
> >>>>> If there is a CompoundPropertyModel in the parents' hierarchy then
> move
> >>>>> your logic to #onComponentTag(), as per Sven's suggestion.
> >>>>> If there is no CPM in the parents then just remove this constructor.
> >>>>>
> >>>>>
> >>>>> public MoneyLabel(String id, Model<? extends BigDecimal>
> >> bigDecimalModel)
> >>>>>>> {
> >>>>>>> super(id, bigDecimalModel);
> >>>>>>> add(new AttributeAppender("class", " number"));
> >>>>>>> if (bigDecimalModel.getObject().doubleValue() < 0.0) {
> >>>>>>> add(new AttributeAppender("class", " negative"));
> >>>>>>> }
> >>>>>>> }
> >>>>>>>
> >>>>>>> In the second constructor I can use the supplied model to determine
> >> to
> >>>>>>> add
> >>>>>>> the negative class. However in the first constructor I cannot find
> a
> >> way
> >>>>>>> to
> >>>>>>> access the model.
> >>>>>>>
> >>>>>>> What am I missing?
> >>>>>>>
> >>>>>>> Ron
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
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> >>>>
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> >>>>
> >>>>
> >>
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> >>
> >>
>
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>
