title: Read ExtendedProperties from Outlook Add-In
body: <p>I am currently setting custom <code>ExtendedProperties</code> on a <code>CalendarFolder</code> using EWS Managed API (C#):</p>
  
  <pre><code>myCalendar.SetExtendedProperty(customExtendedProperty, true);
  </code></pre>
  
  <p>I can also use the Managed API to load those settings when I bind the <code>CalendarFolder</code>:</p>
  
  <pre><code>var myCalendar = CalendarFolder.Bind(service, folderId, requestedPropertySet);
  </code></pre>
  
  <p>I would next like to read these same <code>ExtendedProperties</code>, but from an Outlook Add-In using the Office JavaScript libraries.</p>
  
  <p>From the looks of the the Outlook library does not expose any methods off of <code>Office.context.item</code> to access the <code>ExtendedProperties</code>.</p>
  
  <p>Are there methods in the library that allow me to access this? If not, can I use the schema approach which has the GUID in the URL path (<code>"http://schemas.microsoft.com/mapi/string/{00020329-0000-0000-C000-000000000046}/yourProp"</code>)?</p>