title: How to edit a plist file by key type
body: <p>I want to add into my plist file present in "prefPlist" variable some key with its relative type.</p>
  
  <p>The example content must be:</p>
  
  <pre><code>&lt;dict&gt;
      &lt;key&gt;App Version&lt;/key&gt;
      &lt;string&gt;Beta 1&lt;/string&gt;
      &lt;key&gt;Configuration Type&lt;/key&gt;
      &lt;integer&gt;7&lt;/integer&gt;
      &lt;key&gt;Creation Date&lt;/key&gt;
      &lt;date&gt;27 04 2013, 03:00&lt;/date&gt;
      &lt;key&gt;Want some milk?&lt;/key&gt;
      &lt;true/&gt;
  &lt;/dict&gt;
  </code></pre>
  
  <p>The first key must have the string type, the second the integer type, the third the date time type and the fourth a boolean value.</p>
  
  <p>How can I do this?</p>