docs: def uploader(project, credentials=None):
      """The Uploader is intended for the Fine Uploader used in the web application (or similar frontend), it is not intended for proper RESTful communication. Will return JSON compatible with Fine Uploader rather than CLAM Upload XML. Unfortunately, normal digest authentication does not work well with the uploader, so we implement a simple key check based on hashed username, projectname and a secret key that is communicated as a JS variable in the interface ."""
      postdata = flask.request.values
      if 'user' in postdata:
          user = postdata['user']
      else:
          user = 'anonymous'
      if 'filename' in postdata:
          filename = postdata['filename']
      else:
          printdebug('No filename passed')
          return "{success: false, error: 'No filename passed'}"
      if 'accesstoken' in postdata:
          accesstoken = postdata['accesstoken']
      else:
          return withheaders(flask.make_response("{success: false, error: 'No accesstoken given'}"),'application/json', {'allow_origin': settings.ALLOW_ORIGIN})
      if accesstoken != Project.getaccesstoken(user,project):
          return withheaders(flask.make_response("{success: false, error: 'Invalid accesstoken given'}"),'application/json', {'allow_origin': settings.ALLOW_ORIGIN})
      if not os.path.exists(Project.path(project, user)):
          return withheaders(flask.make_response("{success: false, error: 'Destination does not exist'}"),'application/json', {'allow_origin': settings.ALLOW_ORIGIN})
      else:
          return addfile(project,filename,user, postdata,None, 'json' )