jsf/primefaces dataTable with links; wrong one opened/displayed - jsf

Question

I have a primefaces dataTable with several URLs as data. There is one URL per line. A line has a button. If you click it, a dialog is opened, containing a iframe with the website of the corresponding URL.
This is the (shortened) xhtml:
<p:dataTable id="transResult" rendered="#{not empty urlList}"
var="aUrl"
value="#{urlList}">
<p:column ...></p:column>
...
<p:column>
<p:commandButton id="urlBtn" value="#{aUrl}"
onclick="PF('showURL').show();"/>
<p:dialog id="urlDialog" widgetVar="showURL">
<h:outputLabel value="URL: #{aUrl}"/>
<iframe src="#{aUrl}"/>
</p:dialog>
</p:column>
</p:dataTable>
The table with the buttons is displayed correctly:
|url1|
|url2|
...
If I have a look at the hidden dialogs with firebug, the URLs are put correctly! Also the id's are generated corrctly:
transResult:0:urlDialog
transResult:1:urlDialog
...
Problem:
But when I click on a button, always the dialog with the last URL is openend.
Any idea why this goes wrong?

Answer 1

I found a solution that seems to work. The base is to have different widgetVar.
<p:dataTable id="transResult" rendered="#{not empty urlList}"
var="data"
value="#{urlList}">
<p:column ...></p:column>
...
<p:column>
<p:commandButton id="urlBtn" value="#{aUrl}"
onclick="PF('showURL#{data.id}').show();"/>
<p:dialog id="urlDialog" widgetVar="showURL#{data.id}">
<h:outputLabel value="URL: #{data.aUrl}"/>
<iframe src="#{data.aUrl}"/>
</p:dialog>
</p:column>
</p:dataTable>
So we have an ID per row which is also added to the widgetVar to make them different.
Note that with this solution everything is calculated when the table is created. So there is nothing "dynamic". But for my needs this is no problem.