title: Can't access QML item by id inside SplitView
body: <p>I've began learning QML and I'm getting the following error: </p>
  
  <blockquote>
    <p>ReferenceError: chatTextArea is not defined</p>
  </blockquote>
  
  <p>I have a global function that does something on an item within the same QML file, by id. </p>
  
  <p>For some reason I can't access via the ID of my TextArea, or any item inside of the SplitView. But I am able to manipulate the properties of TabView and each Tab.</p>
  
  <p>My broken code:</p>
  
  <pre><code>import QtQuick 2.2
  import QtQuick.Controls 1.1
  import QtQuick.Layouts 1.1
  
  Rectangle {
  id: lobby
  
  function appendChatMsg(msg) {
      chatTextArea.append(msg) //causes: ReferenceError: chatTextArea is not defined
  }
  
  TabView {
      id: frame
  
      Tab { //I CAN access this item via ID.
          id: controlPage
  
          SplitView {
              anchors.fill: parent
  
              TableView {
                  Layout.fillWidth: true
              }
  
              GridLayout {
                  columns: 1
  
                  TextArea { //This item I CANNOT access via ID.
                      id: chatTextArea
  
                      Layout.fillHeight: true
                      Layout.fillWidth: true
                  }
  
                  TextField {
                      placeholderText: "Type something..."
                      Layout.fillWidth: true
                  }
              }
          }
      }
  }
  }
  </code></pre>
  
  <p>Any idea why chatTextArea is out of scope of my function? Thanks in advance.</p>