CodeMirror: XML code not being indented

I am using CodeMirror to display XML in XML mode, but the code is not being automatically indented.

I checked and the XML mode does implement indent(state, textAfter, fullLine), which handles the indenting, so it should be working.

This is how I am initializing CodeMirror:

CodeMirror.fromTextArea(document.getElementById("test"), {
    mode: 'application/xml',
    theme: 'eclipse',
    lineNumbers: true,
    lineWrapping: true,
    readOnly: true,
    cursorBlinkRate: -1
});

Check this jsFiddle link for a live version: https://jsfiddle.net/zrosfz7x.

Any ideas?

Solution

In order to provide a solution I have added an external beautifier for xml. Here's a complete working example.

<html>
<head>
    <meta charset="UTF-8">
    <link rel=stylesheet href="//codemirror.net/lib/codemirror.css">
    <script src=//codemirror.net/lib/codemirror.js></script>
    <script src=//codemirror.net/mode/xml/xml.js></script>
    <script src="//cdn.rawgit.com/vkiryukhin/vkBeautify/master/vkbeautify.js"></script>
</head>
<body>  
  <textarea id="test"><?xml version="1.0" encoding="UTF-8" ?><note><to>Tove</to><from>Jani</from><heading>Reminder</heading><body>Don't forget me this weekend!</body></note></textarea>
  <script>
    document.getElementById("test").value = vkbeautify.xml(document.getElementById("test").value);
    CodeMirror.fromTextArea(document.getElementById("test"), {
      mode: 'application/xml',
      // theme: 'eclipse',
      lineNumbers: true,
      lineWrapping: true,
      readOnly: true,
      cursorBlinkRate: -1
    });    
  </script>
</body>    
</html>

also here the updated jsFiddle: http://jsfiddle.net/zrosfz7x/3/