I'm in the midst of adding file upload support to my Scalatra application, and I followed the official docs, but the approach doesn't seem to work for ScalatraFilters--only ScalatraServlets.
For example, if I just generate a new Scalatra project, then extend the ScalatraServlet with FileUploadSupport (with configureMultipartHandling beneath as noted, or in the web.xml file), everything works fine, but if I switch that ScalatraServlet to a ScalatraFilter, there doesn't seem to be any support--despite the codebase noting that "FileUploadSupport can be mixed into a [[org.scalatra.ScalatraFilter]] or [[org.scalatra.ScalatraServlet]]".
Does anyone have advice as to how I can include FileUploadSupport when I'm working with a ScalatraFilter rather than a ScalatraServlet? Maybe I'm just missing something obvious, here.