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Howto let Primefaces work with @ConversationScoped Beans?

I build a short page with JSF-Compnents which displays and increments a value from a @ConversationScoped Bean. This page is able to end the Conversation and is getting a new Bean after ending the old Conversation. Here is what it looks like:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
   xmlns:h="http://java.sun.com/jsf/html"
   xmlns:f="http://java.sun.com/jsf/core"
   xmlns:p="http://primefaces.org/ui">
<h:head />
<h:body>
    <h:form>
      <h:outputText id="i" value="#{test.i}" />
      <h:commandButton value="increment" 
         actionListener="#{test.increment}" 
         update="i cid" />
      <h:outputText id="cid" 
         value="#{javax.enterprise.context.conversation.id}" />
      <h:commandButton value="end"
         actionListener="#{test.endConversation}"
         update="i cid" />
    </h:form>
</h:body>
</html>

The code for the Bean is quite simple:

package de.burghard.britzke.test.beans;

import java.io.Serializable;

import javax.annotation.PostConstruct;
import javax.enterprise.context.Conversation;
import javax.enterprise.context.ConversationScoped;
import javax.inject.Inject;
import javax.inject.Named;

@Named
@ConversationScoped
public class Test implements Serializable {

   @Inject Conversation conversation;
   private int i;

   @PostConstruct
   public void init() { 
      conversation.begin(); 
      System.out.println("init conversation"+conversation.getId());
   }

   public int getI() {   return i; }
   public void setI(int i) { this.i = i; }

   public void increment() { i++;System.out.println(i); }

   public void endConversation() {
      System.out.println("ending conversation "+conversation.getId());
      conversation.end();
   }
}

Everything works well, when using the standard h:commandButton Components. But using the Primefaces Components p:commandButton then every click on the 'increment' Button grabs a new Bean instance because the cid-Parameter is not passed to the Server. It has been stated that this is not a primefaces issue. But why is it working with the standard components and not with the primefaces ones? I have been able to pass the cid-Parameter by explicitely embedding a f:param component into the commandButton Components but after destroying the Conversation the parameter is sent with no value producing an error. But it should even work without the f:param component.

Is there a short tutorial how to work with Primefaces and Conversation scoped beans (without explicitely passing the cid-Parameter)?

Solution

  • The problem with the f:param in case of ended conversation has been that the param should not be passed with invalid values (null) for the parameter cid. So correcting this with the following code worked well:

    <!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:p="http://primefaces.org/ui">
<h:head />
<h:body>
    <h:form id="form">
        <h:outputText value="#{test.i}" />
        <p:commandButton value="increment"
            actionListener="#{test.increment}"
            update="@parent">
            <f:param 
                name="#{not empty javax.enterprise.context.conversation.id?'cid':''}"
                value="#{javax.enterprise.context.conversation.id}" />
        </p:commandButton>
        <h:outputText
            value="#{javax.enterprise.context.conversation.id}" />
        <p:commandButton value="end" actionListener="#{test.endConversation}"
            update="@parent">
            <f:param name="cid" value="#{javax.enterprise.context.conversation.id}" />
        </p:commandButton>
    </h:form>
</h:body>
</html>

    But I would like the primefaces components to do the conversation handling without the need for page programmers to explicitly pass a f:param. They should behave like standard JSF (MyFaces) components do.