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I was playing around with primefaces components, when I stumbled upon this issue...

I have a sample page which contains the following,

<h:form>
  <p:panel id="p1">
  <p:commandButton value="display" actionListener="#{myTestBean.display}" update="p2">     </p:commandButton>

  </p:panel>

  <p:panel id="p2" rendered="#{myTestBean.show}">

  <p:inputText value="#{myTestBean.val1}" id="t1"></p:inputText>
  <p:inputText value="#{myTestBean.val2}" id="t2"></p:inputText>
  <p:commandButton value="click me" update="@form" action="#{myTestBean.disply}"></p:commandButton>

  </p:panel>
   </h:form>

My backing bean contains the following,

 public class Testbean implements Serializable {
    private String val1;
  private String val2;

  private boolean show;

    //getters and setters for the above...

        public void display(){

    if(show == false){
        setShow(true);
    }

}

public void disply(){
    System.out.println("I am here");
    val1 = "hi";
    val2 = "hello";
    if(show == false){
        setShow(true);
    }

}
}

Now, the catch here is, when I click my first button(display) the below panel(p2) gets rendered correctly. But when I click on the second button(click me) the panel gets hidden and also on click of second button it never goes to the backing bean method 'disply()'.

I have used action listener in the second button but again the same behavior. Also, I have given the update = "p2" in the second button, even that didn't yield what I wanted.

Could anyone help me out with this and let me know where and what I am doing wrong?

Thank you.

h-kach
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  • This seems to be incomplete or oversimplified code. The `p2` can never be updated this way. Perhaps you were actually updating one of its parent components? – BalusC Jun 16 '12 at 13:44
  • @BalusC its oversimplified code.. Just took a snippet from the original and simplified to zero-in on the problem. I was able to update 'p2' in the above.. why do feel it cant be updated? – h-kach Jun 16 '12 at 16:17
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    Ajax can only update components which are **always** rendered. So if a component is initially not rendered, then Ajax can't update it. It would only work if you update a parent component instead which is always rendered. – BalusC Jun 16 '12 at 18:36
  • @BalusC Ok, I understand..In the above, the button in P1 updates the panel P2 first.. Only after that I am trying to render P2 again using the button in P2. – h-kach Jun 17 '12 at 05:32

4 Answers4

4

The bean needs to be placed in the view scope in order to remember all previous (ajax) actions on the same view. 

@ManagedBean
@ViewScoped
public class TestBean {
    // ...
}

When the bean is placed in the request scope, then the boolean show would be reinitialized to default false and thus the rendered attribute would evaluate false while JSF is looking for the action method to be invoked and hence the action method would be never found and invoked.

See also:

Community
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BalusC
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  • @balusC.. Its working... I am not proficient in using the scopes.. yet to come to terms with that.. :) thanks for the additional info.. – h-kach Jun 16 '12 at 16:27
0

When using actionListener="#{myTestBean.display}", the backinbean method should be

public void display(**ActionEvent event**){

    if(show == false){
        setShow(true);
    }

}

and an ActionEvent parameter must be declared.

adamdunson
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jmuozolvera
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0

I faced the same challenge too. I tried to search online but all in vain. But after several trials, I came to figure out that since I was using the commandButton to set the value of the rendered panel, it was not possible to work out of UIForm, Therefore, I surrounded the commandButton with UIForm and it worked correctly as I wanted.

Jeremy Caney
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Zero - Hero
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I surrounded the button as shown below

<h:form>
    <h:commandButton styleClass="toggle_btn" action="#{buttonNavBean.show()}" style=" font-family: sans-serif; color: black;" value="Sign In/Sign Up"></h:commandButton>
 </h:form>
Suraj Rao
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Zero - Hero
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