URL for Key Filter on document list view in SharePoint 2010

Question

I'm trying to dynamically construct URLs in an ASP.NET MVC website that point back to a SharePoint list view with a Key Filter enabled for a managed metadata field (which uses a TermSet).

If I configure a navigation hierarchy for the managed metadata field, I see the following in the URL: TreeField=MyCategory&TreeValue=0C37852B-34D0-418E-91C6-2AC25AF4BE5B

However, if configure the managed metdata field as a KeyFilter, I see the following in the URL: #ServerFilter=FilterField1=MyCategory-FilterValue1=247-FilterLookupId1=1-FilterOp1=In

Where does the FilterValue1 value of 247 come from? It is not the database id of the MyCategory term. It is also not present anywhere on the Term object when loading the taxonomy through the SharePoint API. Is there a way to construct the query string to use the guid for the term (or better yet, the label, which I know will be unique).

Answer 1

The value comes from the taxonomy hidden list. Use the following method GetWssIdSoftTerm to get the int value the above urls are using to filter the data.

http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.taxonomy.taxonomyfield.getwssidsofterm.aspx