Extending VOs with attributes and creating new treetable columns

Question

Hi,
I am relatively new to the ADF scene so please bear with if what I have in my mind is not even possible with ADF. I have searched hi and lo for a solution and now I thoughts it time to ask the community.
Anyways this is what I want to do. I have a simple DB Table that has a hierarchy i.e Trees with roots much like the Employee hierarchy. Except this table has ids for items that come from external systems ( via Web Services in my case ) and / or ids to items in a table that resides in the local schema. So basically this structure table of mine only has relationships and the detail items need to be joined via an association ( in ADF terminology ) in the treetable component somehow.
* Now creating the structure hierarchy is not a big issue. I have that part done already.
* I have the VO from WS ready that gets the items that I might need to show as detail columns in the tree table.
* Querying the local item Detail VO for detail rows might also be not that problematic.
* Merging the above 2 columns to create a consolidated row set is also not that challenging whereby each column header is premapped to internal and external fields. This mapping is configurable to add more fields as required by a user to the treetable.
What I am struggling with is that when I have this merged row set, how will I make it appear on the UI. The treetable seems to utterly not support this i.e. adding new columns at runtime. Following is what I have been able to establish till now.
* The addDynamicAttribute methods on the View Object are not meant for this purpose. While they do add the attributes and you can set and get them after using this method, they do not render and I can't find a way to dynmically rendering them somehow for tree table.
* Looked at the ADF dynamic components. They support only table and page. No go. Or do the whole tree thing somehow in the table component, Will look odd but might still work.
* Looked at this article ( http://one-size-doesnt-fit-all.blogspot.com/2007/05/back-to-programming-programmatic-adf.html ) . I found a comment in the forum regarding this that this might not be all that efficient. Not to mention the fact that it uses the deprecated TreeModels class in 11g.
** Just regarding this apporach what are the new 11g recommended TreeModel classes to be used instead of the deprecated one. I have read the follow-up post but that just points to the location of where the deprecated classes moved to in 11g under the apache contribution. And makes the example work under 11g. What was this TreeModel class replaced with. Anyone knows ?
** How could I access my VO objects in the TreeTableApater ? Can I declare my merged View object wrapped in a TreeItem POJO object. Theoretically it is on the view layer right ?
** If this approach is inefficient has anyone another solution that might work ?
Or just has anyone managed to extend the treetable in any different sort of way. Any tips/help pointers would be deeply appreciated.
Best Regards,

Answer 1

Hi,
So I had some time to look at this problem again. I created a ChildPropertyTreeModel and binded it to my treetable component and moved the generation of the columns to the jspx page. I got it mostly working but the columns generation part mostly escapes me still.
here is how the jspx page looks like that renders the treetable, and which works fine :
<af:treeTable rowBandingInterval="0" id="dynTTbl" var="row" expandAllEnabled="true"
binding="#{backingBeanScope.DynamicTreeTableBB.dynamicTreeTable}"
value="#{backingBeanScope.DynamicTreeTableModel}">
<f:facet name="nodeStamp">
<af:column sortable="false" headerText="Node Stamp" id="c1">
<af:outputText value="#{row.tableColumnVal[0]}" id="ot1"/>
</af:column>
</f:facet>
<af:forEach begin="1" end="2" varStatus="status">
<af:column>
<f:facet name="header">
<af:outputText value="#{status.index}"/>
</f:facet>
<af:inputText value="#{row.tableColumnVal[status.index]}"/>
</af:column>
</af:forEach>
</af:treeTable>
I want the forEach loop to look a bit differently like below :
<af:forEach items="row.tableColumnVal" var="columnVal" varStatus="status">
<af:column>
<f:facet name="header">
<af:outputText value="#{status.index}"/>
</f:facet>
<af:inputText value="#{columnVal}"/>
</af:column>
</af:forEach>
This should work for a list or array but evidently in my case it is not. I have a suspicion that the "items" attribute is unable to recognize the row.tableColumnVal attribute of mine. I have no way of checking this out or finding out if I am doing something wrong.
My sample project can be found here, if anyone quickly wants to run this on Jdev 11g
http://rapidshare.com/files/438880281/TreeTableTest.zip
P.S. I have tried to convert the tableColumnVal attribute to a List an array and a Map. The first forEach syntax works everytime but the second one fails always and I want the second one to work somehow.
Regards,