Programatically create command button in Primefaces - dynamic

Question

I am trying to create a dynamic form with input text and command button. Everything works fine. But when I click on the command button, the action listener is never called. Please suggest what I am doing wrong or if this is a bug with PF or Mojarra. The code is below
panel = new Panel();
panel.setHeader("Test");
InputText text = new InputText();
final String binding = "#{roleCreateForm.role.name}";
text.setValueExpression("value",
createValueExpression(binding, String.class));
panel.getChildren().add(text);
CommandButton button = new CommandButton();
button.setValue("Save");
MethodExpression me = createMethodExpression("#{roleCreateForm.save}");
button.addActionListener(new MethodExpressionActionListener(me));
panel.getChildren().add(button);
Also the createXXXExpression are below
private MethodExpression createMethodExpression(String action) {
final Class<?>[] paramTypes = new Class<?>[0];
MethodExpression methodExpression = getExpressionFactory()
.createMethodExpression(getELContext(),action, null, paramTypes);
return methodExpression;
}
private ValueExpression createValueExpression(String binding,
Class<String> clazz) {
final ValueExpression ve = getExpressionFactory()
.createValueExpression(getELContext(), binding, String.class);
return ve;
}
public static ELContext getELContext() {
return FacesContext.getCurrentInstance().getELContext();
}
public static ExpressionFactory getExpressionFactory() {
return getApplication().getExpressionFactory();
}
public static Application getApplication() {
return FacesContext.getCurrentInstance().getApplication();
}
My form bean is below
public void save() {
logger.info("Saving role - {}" , role);
}
I am using
Primefaces 3.2, Mojarra 2.1.7, Tomcat 7, JDK 6 , Ubuntu 11
Here is my modified code
Yes I have seen that you have pointed out this as the common mistake. But here is my modified code. This does not work either.
public Panel getPanel() {
if (panel == null) {
panel = new Panel();
panel.setHeader("Test");
panel.setId("dynapanel");
InputText text = new InputText();
text.setId("dynatext");
final String binding = "#{roleCreateForm.role.name}";
text.setValueExpression("value", createValueExpression(binding, String.class));
panel.getChildren().add(text);
CommandButton button = new CommandButton();
button.setValue("Save");
MethodExpression me = getExpressionFactory().createMethodExpression(getELContext(), "#{roleCreateForm.save}", void.class, new Class[0]);
AjaxBehavior ajaxBehavior = new AjaxBehavior();
//ajaxBehavior.setListener( me );
ajaxBehavior.addAjaxBehaviorListener( new AjaxBehaviorListenerImpl( me ) );
button.addClientBehavior( "submit", ajaxBehavior);
panel.getChildren().add(button);
}
return panel;
}

Answer 1

As far as I remember, if you want to invoke a method in your backing bean, use a MethodExpression as a Listener of your AjaxBehaviour:
AjaxBehavior ab1 = new AjaxBehavior();
ExpressionFactory ef = ctx.getApplication().getExpressionFactory();
MethodExpression me1 = ef.createMethodExpression(ctx.getELContext(),
expression,//Your ELExpression #{roleCreateForm.save}
expectedReturnType, //In your case null
expectedParamTypes); //If you receive parameters put new Class[]{Object.class});
ab1.setListener(me1);
button.addClientBehavior( "submit", ab1);

Answer 2

CommandButton btn = ((CommandButton) FacesContext.getCurrentInstance().getViewRoot().findComponent("full id of button"));
try{
FacesContext context = FacesContextWrapper.getCurrentInstance();
MethodExpressionActionListener methodExpression = new MethodExpressionActionListener(context.getApplication().getExpressionFactory()
.createMethodExpression(context.getELContext(),"#{bean.method}", null, new Class[] {ActionEvent.class}));
btn.addActionListener(methodExpression);
}catch(Exception exc){
exc.printStackTrace();
}
and createMethodExpression :
public static MethodExpression createMethodExpression(String expression, Class<?> returnType, Class<?>... parameterTypes) {
FacesContext facesContext = FacesContext.getCurrentInstance();
return facesContext.getApplication().getExpressionFactory().createMethodExpression(
facesContext.getELContext(), expression, returnType, parameterTypes);
}
This works for me ;)