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Posted to users@tapestry.apache.org by Josh Canfield <jo...@thedailytube.com> on 2007/09/27 23:02:40 UTC
Re: [T5]: binding issue: supplying parameter to component --> always null
I'm not well versed in grid/gridcell... but one thing that jumps out is that
you have "_model=_model" in your parameters. Shouldn't that be
"model=_model" ? Also, are you passing the model parameter in your template?
Your Parameter isn't required so null may be the correct value.
I also haven't done inheritance like you are doing, but it looks like you
are redefining the _model attribute from the superclass? Should you maybe be
using datamodel provided by the superclass instead? "model=datamodel"?
http://tapestry.apache.org/tapestry5/tapestry-core/apidocs/org/apache/tapestry/corelib/components/Grid.html
I haven't written the code, but that seems to be what makes sense to me...
Josh
On 9/27/07, Britske <gb...@gmail.com> wrote:
>
>
> Hi all,
>
> I guess I'm missing something here, maybe a trival thing so bear with me
> please.;-)
>
> I'm trying to extend the T5 grid / griddatasource for my requirements. For
> some event-handling in GridColumn I need to reference the field _model of
> type BeanModel which exists in the Grid-class from GridColumn. So I both
> extended Grid --> LazyConfigurableGrid and GridColumns -->
> LazyGridColumns.
>
> next,I supplied field _model as a parameter from the gridclass to the
> gridcolum-class.
>
> My problem:
> _model==null in GridColumn all the time. I guess this is some
> binding-thing
> that I can't quite get my head around. (_model == null on initialization
> of
> the component, but i thought it would be updated later on)
>
> The general question: how to pass objects by reference as parameters,
> since
> they always seem to be null.
>
> the relevant bits:
>
> LazyConfigurableGrid:
> ------------
> @Parameter
> private BeanModel _model;
>
> @SuppressWarnings("unused")
> @Component(parameters =
> { "sortColumnId=sortColumnId", "sortAscending=sortAscending",
> "source=_source", "_model=_model" })
> private LazyGridColumns _columns;
>
>
> LazyGridColumns:
> ------------
> @Parameter
> private BeanModel _model;
>
> Thanks in advance,
> Geert-Jan
>
>
> --
> View this message in context:
> http://www.nabble.com/-T5-%3A-binding-issue%3A--supplying-parameter-to-component---%3E-always-null-tf4530634.html#a12928987
> Sent from the Tapestry - User mailing list archive at Nabble.com.
>
>
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Re: [T5]: binding issue: supplying parameter to component -->
always null
Posted by Britske <gb...@gmail.com>.
you were right on both remarks. I now tried "model=dataModel" but still model
--> null.
could it be (just guessing here) that grid.dataModel isn't initialized (and
thus null) on the moment an action event goes off in the gridcolumns-class?
anyway I looked further in the GridColumns-class and there's a field:
@Parameter(value = "componentResources.container")
private GridModelProvider _dataProvider;
through this the original GridColumns-class is asking for the datamodel i
wanted to get, for instance:
public List<String> getColumnNames() { return
_dataProvider.getDataModel().getPropertyNames(); }
however when i try to access the field in the same manner in my action-event
handler I keep getting null:
void onActionFromSort(String columnId)
{
for (String name : _dataProvider.getDataModel().getPropertyNames()) {
//some code..
}
}
It must be the time of accessing this field in the component life-cycle that
causes this problem I guess. Is this correct? And how to workaround this
issue?
Geert-Jan
Josh Canfield-2 wrote:
>
> I'm not well versed in grid/gridcell... but one thing that jumps out is
> that
> you have "_model=_model" in your parameters. Shouldn't that be
> "model=_model" ? Also, are you passing the model parameter in your
> template?
> Your Parameter isn't required so null may be the correct value.
>
>
> I also haven't done inheritance like you are doing, but it looks like you
> are redefining the _model attribute from the superclass? Should you maybe
> be
> using datamodel provided by the superclass instead? "model=datamodel"?
>
> http://tapestry.apache.org/tapestry5/tapestry-core/apidocs/org/apache/tapestry/corelib/components/Grid.html
>
> I haven't written the code, but that seems to be what makes sense to me...
> Josh
>
>
> On 9/27/07, Britske <gb...@gmail.com> wrote:
>>
>>
>> Hi all,
>>
>> I guess I'm missing something here, maybe a trival thing so bear with me
>> please.;-)
>>
>> I'm trying to extend the T5 grid / griddatasource for my requirements.
>> For
>> some event-handling in GridColumn I need to reference the field _model of
>> type BeanModel which exists in the Grid-class from GridColumn. So I both
>> extended Grid --> LazyConfigurableGrid and GridColumns -->
>> LazyGridColumns.
>>
>> next,I supplied field _model as a parameter from the gridclass to the
>> gridcolum-class.
>>
>> My problem:
>> _model==null in GridColumn all the time. I guess this is some
>> binding-thing
>> that I can't quite get my head around. (_model == null on initialization
>> of
>> the component, but i thought it would be updated later on)
>>
>> The general question: how to pass objects by reference as parameters,
>> since
>> they always seem to be null.
>>
>> the relevant bits:
>>
>> LazyConfigurableGrid:
>> ------------
>> @Parameter
>> private BeanModel _model;
>>
>> @SuppressWarnings("unused")
>> @Component(parameters =
>> { "sortColumnId=sortColumnId", "sortAscending=sortAscending",
>> "source=_source", "_model=_model" })
>> private LazyGridColumns _columns;
>>
>>
>> LazyGridColumns:
>> ------------
>> @Parameter
>> private BeanModel _model;
>>
>> Thanks in advance,
>> Geert-Jan
>>
>>
>> --
>> View this message in context:
>> http://www.nabble.com/-T5-%3A-binding-issue%3A--supplying-parameter-to-component---%3E-always-null-tf4530634.html#a12928987
>> Sent from the Tapestry - User mailing list archive at Nabble.com.
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@tapestry.apache.org
>> For additional commands, e-mail: users-help@tapestry.apache.org
>>
>>
>
>
> --
> --
> TheDailyTube.com. Sign up and get the best new videos on the internet
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>
>
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