5 Replies Latest reply on May 7, 2007 10:29 AM by umk

DataModel: Row is not available

fabricio.lemos Apr 11, 2007 11:49 AM

I had this DataModel bound to the conversation scope

 @DataModel
 public List<Step> getStepList(){
 return useCase.getSteps();
 }

All worked just fine until I changed the association type from List to Set and updated the code to:

 @DataModel
 public Set<Step> getStepList(){
 return useCase.getSteps();
 }

Now the page does not show a new row if a Step is added to the collection. And the console display
ERROR [HtmlTableRendererBase] Row is not available. Rowindex = 0

If I end the conversation and access the page again, the new Step is displayed.

What can be wrong?

Seam version: 1.2.1

thanks in advance,
Fabricio Lemos

1. Re: DataModel: Row is not available

shane.bryzak Apr 16, 2007 7:56 PM (in response to fabricio.lemos)

I believe a DataModel must be a List. Why did you change it to Set?
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2. Re: DataModel: Row is not available

mrobinson28 Apr 16, 2007 9:33 PM (in response to fabricio.lemos)

Is the documentation incorrect?

seam reference docs wrote:

@DataModel

Exposes an attribute of type List, Map, Set or Object[] as a JSF DataModel into the scope of the owning component...

I believe that the standard JSF datatable only supports a limited number of types (not java.util.Set ) which seems to cause problems for one-to-many relationships where the "most natural" type of association is a Set. The hibernate documentation seems to really make a point of this being the most correct mapping where there are not any duplicates but then you can't render it using the stock datatable. The last time I tried it the MyFaces implementation actually "incorrectly" supported the rendering of a Set within a datatable but there were discussions about "fixing" the implementation to not support it.

Can you show how you add to the Collection? and mabye the .xhtml (assuming Facelets)
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3. Re: DataModel: Row is not available

shane.bryzak Apr 16, 2007 11:13 PM (in response to fabricio.lemos)

Can you post some of your code that shows what you're trying to achieve?
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4. Re: DataModel: Row is not available

fabricio.lemos Apr 17, 2007 8:00 AM (in response to fabricio.lemos)

I want a page where I can edit the properties of a UseCase entity. At the end of the page I want to display the Step entities that belong to the UseCase.

This is the page code that I have:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
 xmlns:ui="http://java.sun.com/jsf/facelets"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:s="http://jboss.com/products/seam/taglib">
<body>
<ui:composition template="/template.xhtml">

 <ui:define name="title">
 Editar Caso de Uso
 </ui:define>

 <ui:define name="body">
 <h:form>
 <h:messages />
 Caso de Uso: <h:inputText value="#{useCase.name}" required="true" />
 <h:commandButton value="Inserir Passo" action="insertStep" />
 <h:commandButton value="Atualizar" action="update"
 rendered="${useCase.id != null}" />
 <h:commandButton value="Inserir" action="insert"
 rendered="${useCase.id == null}" />

 <h:dataTable value="#{stepList}" var="stepVar">
 <h:column>
 <f:facet name="header">Nome</f:facet>
 #{stepVar.name}
 </h:column>
 <h:column>
 <f:facet name="header">Editar</f:facet>
 <h:commandLink value="Editar" action="updateStep" />
 </h:column>
 </h:dataTable>
 </h:form>
 </ui:define>

</ui:composition>
</body>
</html>

The "insertStep" commandButton shows another page where I can insert a Step and then go back to the UseCase page. The problem is that the UseCase page does not show the Step added.

When Step collection was a List, the application did work OK.

5. Re: DataModel: Row is not available

umk May 7, 2007 10:29 AM (in response to fabricio.lemos)

For what it's worth, I'm seeing the same behavior with a java.util.Set - doesn't work.

As soon as I changed to java.util.List, the dataTable rendered properly...
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