colVis with serverside processing: Only request visible columns?

Simon79

Is it possible with the current colVis to only request visible columns when using serverside processing? What I mean is that when some columns are hidden, I would like my ajax requests to either not include hidden columns in the columns collection sent to the server, or to include a flag indicating whether the column is visible.

If this is not possible directly, what is the best way in the ajax.data function to determine which columns aren't currently visible due to the user deselecting them through colVis?