title: UI5: Changing from JSON to XML Model -> missing oValue
body: <p>Main Question: I try since 4 days to make Data Binding Work so I made the Program very easy because I thought with a easy MVC it's easy to change from JSON to XML (actualy I want to use RSS Feed as Model later). </p>
  
  <p>So I analyzed console logs and tried everything I found on the official site as well as on Stackoverflow, but I still miss something.</p>
  
  <p>so for the start I have this view:</p>
  
  <pre><code>&lt;core:View 
      xmlns:core="sap.ui.core"
      xmlns="sap.m" 
      controllerName="paketnameAdresse.controller.button"&gt;
  
      &lt;Panel text="Hello World"&gt;
          &lt;Button text="{/text}" press="doSomething"/&gt;
      &lt;/Panel&gt;
  
  &lt;/core:View&gt;
  </code></pre>
  
  <p>and this JSON:
  <code>{"text": "Say Hello"}</code></p>
  
  <p>and this controller :</p>
  
  <pre><code>sap.ui.controller("paketnameAdresse.controller.button", {
  
      onInit : function () { //lädt Model
          var sPath = jQuery.sap.getModulePath("paketnameAdresse", "/data.json");
          var oModel = new sap.ui.model.json.JSONModel(sPath);
      },
  
      doSomething: function () {
          sap.ui.getCore().getEventBus().publish("nav", "to", {
              id : "iconGroup"
          });
      }
  
  });
  </code></pre>
  
  <p>and then i tried everything with XML like:</p>
  
  <pre><code>var oModel = new sap.ui.model.xml.XMLModel();
  oModel.setXML("&lt;?xml version=\"1.0\"?&gt;&lt;text&gt;data&lt;/text&gt;");
  oModel.setData("data.xml");
  oModel.loadData("data.xml");
  </code></pre>
  
  <p>with the following XML: </p>
  
  <p>
  Say Hello</p>
  
  <p>In the Document data.xml as well in the controller</p>
  
  <p>Where did I go wrong?</p>
  
  <p>PS: Side Questions:</p>
  
  <p>What I do have to know about RSS? Do things change?
  How I get XML / RSS via HTTP get/via URL?
  When it comes to update Methods, is it best to use a POST Method? 
  If No, which Method is best?</p>
  
  <p>PSS: 
  console logs:</p>
  
  <p><strong>JSON:</strong></p>
  
  <p><img src="https://i.stack.imgur.com/dqcHb.png" alt="JSON Console Screenshot"></p>
  
  <p>oValue: "Say Hello"</p>
  
  <p>sInternalType: "string"</p>
  
  <p>sMode: "TwoWay"</p>
  
  <p><strong>XML</strong></p>
  
  <p><img src="https://i.stack.imgur.com/6TQwZ.png" alt="XML Console Screeenshot"></p>
  
  <p>oValue: ""</p>
  
  <p>sInternalType: "string"</p>
  
  <p>sMode: "TwoWay"</p>