static Renderer getRenderer(final FacesContext context, final UIComponent component) {
final String rendererType = component.getRendererType();
if (rendererType == null) {
return null;
}
final RenderKit renderKit = RenderKitUtil.getRenderKit(context);
return renderKit.getRenderer(component.getFamily(), rendererType);
}
public static String getWidgetVar(String id) {
UIComponent component = findComponent(FacesContext.getCurrentInstance().getViewRoot(), id);
Renderer renderer =
FacesContext.getCurrentInstance()
.getRenderKit()
.getRenderer(component.getFamily(), component.getRendererType());
if (component == null) throw new FacesException("Cannot find component " + id + " in view.");
else if (!(renderer instanceof CoreRenderer))
throw new FacesException("Component with id " + id + " is not derived from CoreRenderer.");
return ((CoreRenderer) renderer).resolveWidgetVar(component);
}
private static UIComponent findLabelFor(UIComponent root, String clientId) {
for (UIComponent c : (List<UIComponent>) root.getChildren()) {
if ("javax.faces.Label".equals(c.getRendererType())) {
String labelFor = (String) c.getAttributes().get("for");
if (clientId.equals(labelFor) || clientId.endsWith(":" + labelFor)) {
return c;
}
}
if (c.getChildCount() > 0) {
// look for the right label recursively
UIComponent label = findLabelFor(c, clientId);
if (label != null) {
return label;
}
}
}
return null;
}