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Posted to users@myfaces.apache.org by fastbob <fa...@gmail.com> on 2007/02/13 03:41:23 UTC
Re: [Solved] Dynamic panelGrid within dataTable
Simon,
Thanks for your quick response. Obviously I don't understand the rendering
model sufficiently. This helps.
Yes, what I'm attempting does imply a tight coupling between the
presentation and backing bean, but in this case the backing bean is actually
used just for presentation and delegates to a more general backing bean. So
I can live with this instance.
Is there a preferred JSF pattern for communicating user selection of a
dataTable row back to the server? I've found a number of somewhat crufty
methods (such as on BalusC), but unless I've missed something, none seem
particularly attractive other than f:attribute. But perhaps that's just the
nature of the beast. Any suggestions?
Thanks.
fastbob
--
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Re: [Solved] Dynamic panelGrid within dataTable
Posted by fastbob <fa...@gmail.com>.
Simon,
Sorry for creating confusion. When I'm saying "dynamic generation,"
specifically I'm generating a panelGrid.
To expand on your latest example, imagine that for different types of people
(teacher, CEO, banker) you have to display different details for searching,
e.g., grade level drop-down for teachers, a check box if the CEO manages a
multi-national company, etc. You also don't know in advance the exact number
and format of the parameters, since these are retrieved from an external XML
description. And to be complete, these generated fields are displayed via
detailToggler when the user clicks on a person.
So your example becomes something like:
<t:dataTable var="currPersonHandler" ....>
<t:panelGrid binding="#{something_other_than_currPersonHandler}"/>
...
It would be great if panelGrid accepted a value attribute, but apparently it
doesn't.
I'm open to suggestions, up to suggesting I'm crazy to even consider this
(that's already an established fact).
fastbob
Simon Kitching-3 wrote:
>
> Hi,
>
> When you say "dynamic generation", do you mean CGLIB or similar? This
> approach *does* work (and is used in the project I'm currently working
> on) but I didn't mean to imply that with my comment.
>
> To expand on my example below, if a table of Person objects has a column
> containing:
> <t:dataTable var="currPerson" ....>
> <t:outputText value="#{currPerson.name}"/>
>
> then this can be converted to be a table of PersonHandler objects, and
> the jsp can be updated to:
>
> <t:dataTable var="currPersonHandler" ....>
> <t:outputText value="#{currPersonHandler.person.name}"/>
> ...
> <h:commandLink action="#{currPersonHandler.doSomething}"/>
>
> All that is needed is for the PersonHandler objects to have a
> getPerson() method. No "dynamic generation" required. And the
> doSomething method obviously knows which Person to modify - the Person
> it wraps.
>
> Regards,
>
> Simon
>
>
> fastbob wrote:
>> Hmmm. I think you're spot on with your comment about putting the
>> functionality into the row object itself. That's what I was trying to do
>> when I erroneously attempted to bind to the dataTable var. Each row
>> object
>> would be responsible for generating the appropriate components. But it
>> sounds like the row object can only be accessed through its parent
>> dataTable, which I suppose makes some sense.
>>
>> It finally dawned on me that I need to deal with the dynamic generation
>> at
>> two points - the rendering of the HTML and when the values are posted
>> back
>> to the server. The latter I think I can deal with, but the former has me
>> scratching my head. It seems like I'll need to generate the dynamic
>> components at the same time I initialize the dataTable list (perhaps in a
>> map), and then refer to those components in the column definitions.
>>
>> fastbob
>>
>>
>> Simon Kitching-3 wrote:
>>> fastbob wrote:
>>>> Is there a preferred JSF pattern for communicating user selection of a
>>>> dataTable row back to the server? I've found a number of somewhat
>>>> crufty
>>>> methods (such as on BalusC), but unless I've missed something, none
>>>> seem
>>>> particularly attractive other than f:attribute. But perhaps that's just
>>>> the
>>>> nature of the beast. Any suggestions?
>>> Generally when processing a row the nicest solution is to build any
>>> functionality needed onto the row object itself. Suppose the model is
>>> normally a list of Person objects but some logic is needed to manipulate
>>> a particular person then the model can be changed to a list of
>>> PersonHandler objects each of which has a "person" property. In this
>>> case, there is no "communication of the user selection" required; the
>>> method is invoked *on* the selected object.
>>>
>>> An alternative is to set the "binding" attribute on the t:dataTable
>>> object, then the callback method that is invoked can call the getRowData
>>> method on the datatable to find the row "currently being operated on".
>>> It's not so elegant but does work fine.
>>>
>>> I think that if you write the commandLink to invoke an ActionListener
>>> rather than an action method then the event might also have the
>>> appropriate row info but am not sure of the details here.
>>>
>>> Regards,
>>>
>>>
>>> Simon
>>>
>>>
>>
>
>
>
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Re: [Solved] Dynamic panelGrid within dataTable
Posted by Simon Kitching <si...@rhe.co.nz>.
Hi,
When you say "dynamic generation", do you mean CGLIB or similar? This
approach *does* work (and is used in the project I'm currently working
on) but I didn't mean to imply that with my comment.
To expand on my example below, if a table of Person objects has a column
containing:
<t:dataTable var="currPerson" ....>
<t:outputText value="#{currPerson.name}"/>
then this can be converted to be a table of PersonHandler objects, and
the jsp can be updated to:
<t:dataTable var="currPersonHandler" ....>
<t:outputText value="#{currPersonHandler.person.name}"/>
...
<h:commandLink action="#{currPersonHandler.doSomething}"/>
All that is needed is for the PersonHandler objects to have a
getPerson() method. No "dynamic generation" required. And the
doSomething method obviously knows which Person to modify - the Person
it wraps.
Regards,
Simon
fastbob wrote:
> Hmmm. I think you're spot on with your comment about putting the
> functionality into the row object itself. That's what I was trying to do
> when I erroneously attempted to bind to the dataTable var. Each row object
> would be responsible for generating the appropriate components. But it
> sounds like the row object can only be accessed through its parent
> dataTable, which I suppose makes some sense.
>
> It finally dawned on me that I need to deal with the dynamic generation at
> two points - the rendering of the HTML and when the values are posted back
> to the server. The latter I think I can deal with, but the former has me
> scratching my head. It seems like I'll need to generate the dynamic
> components at the same time I initialize the dataTable list (perhaps in a
> map), and then refer to those components in the column definitions.
>
> fastbob
>
>
> Simon Kitching-3 wrote:
>> fastbob wrote:
>>> Is there a preferred JSF pattern for communicating user selection of a
>>> dataTable row back to the server? I've found a number of somewhat crufty
>>> methods (such as on BalusC), but unless I've missed something, none seem
>>> particularly attractive other than f:attribute. But perhaps that's just
>>> the
>>> nature of the beast. Any suggestions?
>> Generally when processing a row the nicest solution is to build any
>> functionality needed onto the row object itself. Suppose the model is
>> normally a list of Person objects but some logic is needed to manipulate
>> a particular person then the model can be changed to a list of
>> PersonHandler objects each of which has a "person" property. In this
>> case, there is no "communication of the user selection" required; the
>> method is invoked *on* the selected object.
>>
>> An alternative is to set the "binding" attribute on the t:dataTable
>> object, then the callback method that is invoked can call the getRowData
>> method on the datatable to find the row "currently being operated on".
>> It's not so elegant but does work fine.
>>
>> I think that if you write the commandLink to invoke an ActionListener
>> rather than an action method then the event might also have the
>> appropriate row info but am not sure of the details here.
>>
>> Regards,
>>
>>
>> Simon
>>
>>
>
Re: [Solved] Dynamic panelGrid within dataTable
Posted by fastbob <fa...@gmail.com>.
Hmmm. I think you're spot on with your comment about putting the
functionality into the row object itself. That's what I was trying to do
when I erroneously attempted to bind to the dataTable var. Each row object
would be responsible for generating the appropriate components. But it
sounds like the row object can only be accessed through its parent
dataTable, which I suppose makes some sense.
It finally dawned on me that I need to deal with the dynamic generation at
two points - the rendering of the HTML and when the values are posted back
to the server. The latter I think I can deal with, but the former has me
scratching my head. It seems like I'll need to generate the dynamic
components at the same time I initialize the dataTable list (perhaps in a
map), and then refer to those components in the column definitions.
fastbob
Simon Kitching-3 wrote:
>
> fastbob wrote:
>> Is there a preferred JSF pattern for communicating user selection of a
>> dataTable row back to the server? I've found a number of somewhat crufty
>> methods (such as on BalusC), but unless I've missed something, none seem
>> particularly attractive other than f:attribute. But perhaps that's just
>> the
>> nature of the beast. Any suggestions?
>
> Generally when processing a row the nicest solution is to build any
> functionality needed onto the row object itself. Suppose the model is
> normally a list of Person objects but some logic is needed to manipulate
> a particular person then the model can be changed to a list of
> PersonHandler objects each of which has a "person" property. In this
> case, there is no "communication of the user selection" required; the
> method is invoked *on* the selected object.
>
> An alternative is to set the "binding" attribute on the t:dataTable
> object, then the callback method that is invoked can call the getRowData
> method on the datatable to find the row "currently being operated on".
> It's not so elegant but does work fine.
>
> I think that if you write the commandLink to invoke an ActionListener
> rather than an action method then the event might also have the
> appropriate row info but am not sure of the details here.
>
> Regards,
>
>
> Simon
>
>
--
View this message in context: http://www.nabble.com/Dynamic-panelGrid-within-dataTable-tf3218128.html#a8970885
Sent from the MyFaces - Users mailing list archive at Nabble.com.
Re: [Solved] Dynamic panelGrid within dataTable
Posted by Simon Kitching <si...@rhe.co.nz>.
fastbob wrote:
> Simon,
> Thanks for your quick response. Obviously I don't understand the rendering
> model sufficiently. This helps.
>
> Yes, what I'm attempting does imply a tight coupling between the
> presentation and backing bean, but in this case the backing bean is actually
> used just for presentation and delegates to a more general backing bean. So
> I can live with this instance.
>
> Is there a preferred JSF pattern for communicating user selection of a
> dataTable row back to the server? I've found a number of somewhat crufty
> methods (such as on BalusC), but unless I've missed something, none seem
> particularly attractive other than f:attribute. But perhaps that's just the
> nature of the beast. Any suggestions?
Generally when processing a row the nicest solution is to build any
functionality needed onto the row object itself. Suppose the model is
normally a list of Person objects but some logic is needed to manipulate
a particular person then the model can be changed to a list of
PersonHandler objects each of which has a "person" property. In this
case, there is no "communication of the user selection" required; the
method is invoked *on* the selected object.
An alternative is to set the "binding" attribute on the t:dataTable
object, then the callback method that is invoked can call the getRowData
method on the datatable to find the row "currently being operated on".
It's not so elegant but does work fine.
I think that if you write the commandLink to invoke an ActionListener
rather than an action method then the event might also have the
appropriate row info but am not sure of the details here.
Regards,
Simon