JSF: How to attach an actionListener to component created programatically

Question

I have to create some commandLinks dynamically and attach some action listener to it, So I've put on the JSP page and used such code to add the commandLinks and to assign action listeners to:

public ManagedBean(){
 List<UIComponenet> child = panelGrid.getChilderen();
 list.clear();

 List<MyClass> myList = getSomeList();

 for (MyClass myObj : myList){
   FacesContext ctx = FacesContext.getCurrentContext();
   HtmlCommandLink cmdLink = (HtmlCommandLink) ctx.getApplication.createComponent(HtmlCommandLink.COMPONENT_TYPE);
   cmdLink.setValue(myObj.getName());
   cmdLink.setActionLinstner(new ActionListener(){
     public void processAction(ActionEvent event) throws AbortProcessingException{
       System.out.println (">>>>>>>>>>>>>>>>>I am HERE ");
     }
   });
   child.add(cmdLink);
 }
}

But Unfortunately, When I press this commandLinks, an exception thrown! Could you please help me how to add componenet's event listeners at runtime?

(Note, the code above my contain syntax/compilation errors as I just wrote)

Answer 1

First, you need to manually assign ID to any dynamically created UINamingContainer, UIInput and UICommand components. Otherwise JSF can't locate them in the component tree based on the request parameters, because it wouldn't match the autogenerated ID's.

Thus, at least do:

HtmlCommandLink link = new HtmlCommandLink();
link.setId("linkId");
// ...

Second, you're supposed to create an ActionListener as MethodExpression as follows:

FacesContext context = FacesContext.getCurrentInstance();
MethodExpression methodExpression = context.getApplication().getExpressionFactory().createMethodExpression(
    context.getELContext(), "#{bean.actionListener}", null, new Class[] { ActionEvent.class });

link.addActionListener(new MethodExpressionActionListener(methodExpression));
// ...

...and of course have the following method in the backing bean class behind #{bean}:

public void actionListener(ActionEvent event) {
    // ...
}

All the above dynamic stuff basically does the same as the following raw JSF tag:

<h:commandLink id="linkId" actionListener="#{bean.actionListener}" />