RF4: a4j:jsFunction and a4j:param

[alexanndre.granier]

Hi,

I need to retrieve wich node has been clicked. I use the jsFunction tag with a param like this

<h:form>
            <a4j:jsFunction name="func" actionListener="#{myBean.action}" render="@form">
                <a4j:param name="param1" assignTo="#{myBean.idx}"/>
            </a4j:jsFunction>
           
            <a4j:repeat value="#{myBean.nodes}" var="node" rowKeyVar="key" rows="30">
                <a4j:outputPanel id="panel" layout="block" onclick="func(#{key});">
                    <h:outputText value="#{node.label}  key: #{key}"/>
                </a4j:outputPanel>
            </a4j:repeat>
</h:form>

Here is the managed bean

@ManagedBean
@ViewScoped
public class MyBean {
    private List<Node>     nodes;
   
    private long idx;

public MyBean() {
        nodes = new ArrayList<Node>();
        nodes.add(new Node("node1"));
        nodes.add(new Node("node2"));
}

public void action(ActionEvent event) {
     System.out.println("action "+this.getIdx());
}
...
}




}

When the click event occur on the label, the index is passed to the bean.

It works but the index is the one of the last request...

As a work around I can get the param using the FacesContext object

FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("param1")

but why this behavior ?

[bleathem]

Alexandre Granier wrote:

It works but the index is the one of the last request...

In what phase are you observing that the index is stale?  Can you inspect the browser headers of the POST to see if it is POSTing the expected value?

[alexanndre.granier]

Thanks Brian,

If you talk about jsf phase, it is during the invoke application phase

here is the trace:

INFO: PWC1412: WebModule[null] ServletContext.log():before INVOKE_APPLICATION 5

INFO: action 0

INFO: PWC1412: WebModule[null] ServletContext.log():after INVOKE_APPLICATION 5

here is the post values after one click on the second node, param1 is good in the post:

1. j_idt6:j_idt6
2. javax.faces.ViewState:2398871897211749917:8963538410607719053
3. javax.faces.source:j_idt6:j_idt7
4. javax.faces.partial.execute:j_idt6:j_idt7 @component
5. javax.faces.partial.render:@component
6. param1:1
7. org.richfaces.ajax.component:j_idt6:j_idt7
8. j_idt6:j_idt7:j_idt6:j_idt7
9. rfExt:null
10. AJAX:EVENTS_COUNT:1
11. javax.faces.partial.ajax:true

does it help ?

[bleathem]

I created an Arquillian Warp test to verify the behaviour:

https://github.com/richfaces/richfaces/commit/96b4fc65337e8dee99e55b1adf44261e3ef5b59b#L1R112

Notice how before the INVOKE_APPLICATION phase the bean property is not set, but after the INVOKE_APPLICATION phase the bean property is set.  This is consistent with your report that it is not set *at some point* during the INVOKE_APPLICATION phase.

The reason for this is that the r:param (a4j:param) component is decoded as an ActionListener, see:

https://github.com/richfaces/richfaces/blob/master/framework/src/main/java/org/richfaces/ui/ajax/parameter/AbstractParameter.java#L93

In your example above, your ActionListener is simply executed prior to the r:param ActionListener.

An alternative means of accomplishing your goal would be to use a javascript click listener to set the value of a hidden input, and execute that input with your ajax request.  This would apply the value to your backing bean in the UPDATE_MODEL_VALUES phase, prior to the INVOKE_APPLICATION.

[alexanndre.granier]

Ok, I use this trick:

<a4j:jsFunction name="func" actionListener="#{myBean.action}" render="@form" execute="@form"/>
<h:inputHidden id="param1" value="#{myBean.idx}"/>
           
<a4j:repeat value="#{myBean.nodes}" var="node" rowKeyVar="key" rows="30">
      <a4j:outputPanel id="panel" layout="block" onclick="jQuery(#{rich:element('form:param1')}).val(#{key});func();">
            <h:outputText value="#{node.label}  key: #{key}"/>
      </a4j:outputPanel>
</a4j:repeat>

I had to use the "execute" attribute to process the inputHidden.

thx for your help

[bleathem]

Note, this issue is tracked via the jira:

[#RF-11446] a4j:jsFunction actionListener= method called before a4j:param assignTo setter - JBoss Issue Tracker

with the recommend workaround of using the action attribute of the jsFunction, rather than the actionListener.