JSF Method to Recursively Find Component in Component Tree

Whenever you want to find a component in the component tree, you can use:

• JSF native findComponent()
• JSF native invokeOnComponent()
• OmniFaces findComponentRelatively()
• OmniFaces findComponentInParents()
• OmniFaces findComponentInChildren()

But, sometimes you need to get down to the most time consuming search. Use, this approach as the last solution (pass to it the component tree/sub-tree in which to search and the clientId of the component to find - if the searched component cannot be found, this method returns null):

import static org.omnifaces.util.Utils.isEmpty;
...
private static <C extends UIComponent> C findComponentRecursively(UIComponent component, String clientId) {

 if (isEmpty(clientId)) {

     return null;

 }

 for (UIComponent child : component.getChildren()) {

      UIComponent result;

      try {

          result = child.findComponent(clientId);

      } catch (IllegalArgumentException e) {

        continue;

      }

      if (result == null) {

          result = findComponentRecursively(child, clientId);

     }

     if (result != null) {

         return (C) result;

     }

 }

 return null;

}

Examples:

JSF page snippet

...

<h:body> 

 <h:graphicImage id="myImageId" url="http://1.bp.blogspot.com/-

  gtjrtr50mMY/VL0IcD0hbrI/AAAAAAAAA-I/8fmOugRBkvU/s1600/omniutil.png"/>

 <h:form id="myFormId">

  <h:panelGrid id="panelId">             

   Some text

   <h:outputText id="myOutputId" value="..." />

   <h:panelGroup id="myDivId" layout="block">

    <h:inputText id="myInputId" value="..."/>                                     

   </h:panelGroup>

   <h:commandButton id="myButtonId" value="Click me!" />           

  </h:panelGrid>

 </h:form>

</h:body>

...

·         search from UIViewRoot the component with clientId myImageId

UIComponent found = findComponentRecursively(UIViewRoot, "myImageId");

·         search from UIViewRoot the component with id, myInputId / clientId, myFormId:myInputId

UIComponent found = findComponentRecursively(UIViewRoot, "myInputId");

//this will perform faster

UIComponent found = findComponentRecursively(UIViewRoot, "myFormId:myInputId");

Note  Whenever you can, is better to use clientIds instead of ids, because the search perform faster.