Unable to get component by id in the bean [duplicate] - jsf

Question

This question already has answers here:
Find component by ID in JSF
(5 answers)
Closed 1 year ago.
I tried to do in a ManagedBean:
UIComponent a = FacesContext.getCurrentInstance().getViewRoot().findComponent("a:b");
I checked with the chrome browser inspector, and the component has id "a:b". But debugging the code, I get the UIComponent equal to null.
I tried with all the combinations: ":a:b", ":b", "b", "\\:a\\:b"...
I'm using Primefaces 3.4.1 with Mojarra 2.1.7
UPDATE: I also tried as suggested in the comments:
UIComponent container = FacesContext.getCurrentInstance().getViewRoot().findComponent("a");
UIComponent b = ((UIComponentBase) container).findComponent("b");
container is not null, but b is null

Answer 1

Solved inspired to Abbas Gadhia's answer:
public class JsfUtil {
public static UIComponent findComponent(String id) {
FacesContext context = FacesContext.getCurrentInstance();
UIComponent root = context.getViewRoot();
UIComponent res = root.findComponent(id);
return res;
}
public static UIComponent findSubComponent(final String id, UIComponent container) {
FacesContext context = FacesContext.getCurrentInstance();
if (container == null) {
container = context.getViewRoot();
}
String idContainer = container.getId();
if (id.equals(idContainer)) {
return container;
}
final UIComponent[] found = new UIComponent[1];
VisitContext visitContext = VisitContext.createVisitContext(context);
container.visitTree(visitContext, new VisitCallback() {
#Override
public VisitResult visit(
VisitContext context,
UIComponent component
) {
String idComponent = component.getId();
if (id.equals(idComponent)) {
found[0] = component;
return VisitResult.COMPLETE;
}
return VisitResult.ACCEPT;
}
});
return found[0];
}
}
Usage:
UIComponent container = JsfUtil.findComponent("containerId");
UIComponent element = JsfUtil.findSubComponent("lastPartOfElementId", container);