Find component by ID in JSF

I want to find some UIComponent from managed bean by the id that I have provided.

I have written the following code:

private UIComponent getUIComponent(String id) {  
      return FacesContext.getCurrentInstance().getViewRoot().findComponent(id) ;  
}

I have defined a p:inputTextarea as:

<p:inputTextarea id="activityDescription" value="#{adminController.activityDTO.activityDescription}" required="true" maxlength="120"
    autoResize="true" counter="counter" counterTemplate="{0} characters remaining." cols="80" rows="2" />

Now if a call to the method as getUIComponent("activityDescription") it is returning null, but if I call it as getUIComponent("adminTabView:activityForm:activityDescription") then I can get the org.primefaces.component.inputtextarea.InputTextarea instance.

Is there any way to get the component with only the id i.e., "activityDescription" not the absolute id i.e., "adminTabView:activityForm:activityDescription"?

Solution 1:

You can use the following code:

public UIComponent findComponent(final String id) {

    FacesContext context = FacesContext.getCurrentInstance(); 
    UIViewRoot root = context.getViewRoot();
    final UIComponent[] found = new UIComponent[1];

    root.visitTree(new FullVisitContext(context), new VisitCallback() {     
        @Override
        public VisitResult visit(VisitContext context, UIComponent component) {
            if (component != null 
                && id.equals(component.getId())) {
                found[0] = component;
                return VisitResult.COMPLETE;
            }
            return VisitResult.ACCEPT;              
        }
    });

    return found[0];

}

This code will find only the first component in the tree with the id you pass. You will have to do something custom if there are 2 components with the same name in the tree (this is possible if they are under 2 different naming containers).

Solution 2:

I try this code, and it's help:

private static UIComponent getUIComponentOfId(UIComponent root, String id){
    if(root.getId().equals(id)){
        return root;
    }
    if(root.getChildCount() > 0){
        for(UIComponent subUiComponent : root.getChildren()){
                UIComponent returnComponent = getUIComponentOfId(subUiComponent, id);
                if(returnComponent != null){
                    return returnComponent;
            }
        }
    }
    return null;
}

Thanks

Solution 3:

Maybe it's not possible. The FacesContext.getCurrentInstance().getViewRoot().findComponent(id) method returns only one UIComponent. The ViewRoot is constructed as a tree so if you have two forms in the view, each one with a component with id="text", they will have it's parent components added to the id so they won't conflict. If you put the two id="text" components within the same form, you will have java.lang.IllegalStateException thrown.

If you want to find all components with the searched id, you could write a method that implements:

List<UIComponent> foundComponents = new ArrayList();
for(UIComponent component: FacesContext.getCurrentInstance().getViewRoot().getChildren()) {
    if(component.getId().contains("activityDescription")){
        foundComponents.add(component);
    }
}

Or if you want to find the first occurrence:

UIComponent foundComponent;
for(UIComponent component: FacesContext.getCurrentInstance().getViewRoot().getChildren()) {
    if(component.getId().contains("activityDescription")){
        foundComponent = component;
        break;
    }
}

Solution 4:

Just put prependId="false" to your form in which this textarea is.