Please help me, urgent, waiting online

[seto]

Click the s:link and report Exception during INVOKE_APPLICATION(5): java.lang.IllegalArgumentException: attempt to create merge event with null entity. But the data of product.name is displayed normal. And it seems that the problem is the passing parameter of s:link.

 <ui:repeat value="#{productCCList}" var="productCC">
 <tr>
 <td width="91" height="100%">
 <table width="100%" height="100%" border="1" cellspacing="0"
 cellpadding="0">
 <tr>
 <td>
 <div align="center" style="font-size: 14px;">#{productCC.name}</div>
 </td>
 </tr>
 </table>
 </td>
 <td>
 <table width="100%" border="1" cellspacing="0" cellpadding="0">
 <ui:repeat value="#{productCC.c}" var="productC">
 <tr>
 <td height="50">
 <div align="center" style="font-size: 14px;">#{productC.name}</div>
 </td>
 <ui:repeat value="#{productC.product}" var="product">
 <td>
 <div align="center" style="font-size: 14px;"><s:link
 id="viewProduct" value="#{product.name}"
 action="#{hongyangManager.selectProduct(product)}" /></div>
 </td>
 </ui:repeat>
 </tr>
 </ui:repeat>
 </table>
 </td>
 </tr>
 </ui:repeat>

@Stateful
@Name("hongyangManager")
public class HongyangManagerAction implements HongyangManager {

 @PersistenceContext(type = PersistenceContextType.EXTENDED)
 EntityManager em;

 @DataModel
 List productCCList;

 Product currentProduct;

 XD currentXD;

 YD currentYD;

 @Factory
 public void getProductCCList() {
 productCCList = em.createQuery("from ProductCC productCC")
 .getResultList();
 }

 public String selectProduct(Product selectedProduct) {
 currentProduct = em.merge(selectedProduct);
 return "product";
 }

 public String selectXD(XD selectedXD) {
 currentXD = em.merge(selectedXD);
 return "xd";
 }

 public String selectYD(YD selectedYD) {
 currentYD = em.merge(selectedYD);
 return "yd";
 }

 @Destroy
 @Remove
 public void destroy() {
 }
}

[pmuir]

Do you have the el extension correctly working elsewhere in your app? I take it product is null if you debug the call to selectProduct?

[seto]

If the product is null and the product.name won't display correctly, right? I admit that it should be some mistake I haven't notice, but I can't find it.

[pmuir]

That wasn't really what I was asking. I was trying to check whether you had the EL extensions that Seam uses to support passing parameters to action methods in EL correctly set up.

[seto]

el extension?
the el-api.jar and el-ri.jar?
I set up it just as the booking example

<application>
 <display-name>HongYang</display-name>

 <module>
 <web>
 <web-uri>hongyang.war</web-uri>
 <context-root>/hongyang</context-root>
 </web>
 </module>
 <module>
 <ejb>hongyang.jar</ejb>
 </module>
 <module>
 <java>jboss-seam.jar</java>
 </module>
 <module>
 <java>el-api.jar</java>
 </module>
 <module>
 <java>el-ri.jar</java>
 </module>

</application>

[seto]

Or tell me how I could set up the extensions correctly. I don't use the parameter elsewhere

[seto]

If you means the configuration mentioned in the documentation, I just set up as the booking example.

 <context-param>
 <param-name>org.ajax4jsf.VIEW_HANDLERS</param-name>
 <param-value>org.jboss.seam.ui.facelet.SeamFaceletViewHandler</param-value>
 </context-param>

[shane.bryzak]

EL parameters are simply an alternative to using @In. The parameters will be evaluated as value expressions, so they already need to exist in some scope when the action method is invoked. Using them to list objects in a collection using a <ui:repeat> tag won't produce a list of items that can each be clicked to select that item.

[seto]

I used the dataTable making no effect either. It seems that it isn't the problem of the tag.

[christian.bauer]

It's a problem of you not understanding the JSF lifecycle and processing phases :)

Chapter 9: http://java.sun.com/javaee/5/docs/tutorial/doc/

[seto]

Thanks for shane.bryzak, I realize the problem now. But I don't know how to solve it. To solve the problem I have to use the pull style restful method?

[seto]

Thanks for shane.bryzak's and christian.bauer's help, I realize the problem now. To solve the problem, I have to use the pull style programming?

[seto]

Some one help me?

[shane.bryzak]

I recommend you use a dataTable. There's plenty of sample code within the Seam examples, I'd take a look at the Booking example first.

[seto]

No, I means that the datatable wouldn't help either. Because the parameter to pass is the sub-objects in the datamodel ProductCCList. It isn't a datamodel, so the parameter passing not work. Just as christian.bauer said, the parameter should be the varible in the scope, so the product list don't work. So what else can be used except pull style?