Why doesn't Windows Explorer display OpenSearch results with types other than text/html correctly?

Question

I'm trying to display results from the REST API of IBM Content Analytics in Windows 7 Explorer through its OpenSearch integration. The REST API returns an Atom feed with an <atom:entry> element for each search hit.

My problem is: As soon as the type attribute of an element's <atom:link> has a value other than text/html, the respective search hit in Windows explorer is displayed as "No information available". In the below minimal example, the search hit is displayed correctly as soon as you remove the type="application/msword" or change its value to text/html.

<atom:entry>
  <atom:title>Hit B</atom:title>
  <atom:link rel="alternate" type="application/msword" href="http://192.168.111.130:8394/api/v10/document/content?collection=Search&amp;uri=file:///C:/DataFiles/Price%2BChange.doc" hreflang="en"/>
  <atom:id>file:///C:/DataFiles/Price+Change.doc</atom:id>
  <atom:summary>...B</atom:summary>
</atom:entry>

Can anyone explain this behaviour or say how to avoid it and display non-text/html results in Windows Explorer?

Documentation seems scarce, most of the stuff I found was in the two documents linked below, but I didn't find anything on this issue there.

• http://msdn.microsoft.com/en-us/library/windows/desktop/dd940453%28v=vs.85%29.aspx
• http://windowsteamblog.com/windows/b/developers/archive/2010/04/18/windows-7-federated-search.aspx

Answer 1

In RSS, the link tag needs to contain a URL e.g.

<link>http://www.google.com</link>. 

Then the title, date, etc. are displayed in the file manager.

Instead

<link href="http://www.google.com" /> 

would show "No information available" in the file manager.

For ATOM, you need to include:

<link href="http://www.google.com" />

without any "rel" attribute. Then you see the correct information in the file manager!