         c.path = payload
         c.updateProxy()
 
+    c.outPorts.add 'error',
+      datatype: 'object'
+
     # helper function to add ports
     addInPort = (component, prop) ->
       portName = prop.name.replace(/[^A-Za-z0-9_]/g, '_').toLowerCase()

      return unless @proxy
      delete @proxy

    c.setProperty = (propName, value) ->
      return unless @bus and @path
      log "set #{propName} = #{value}"
      @getProxy()[propName] = value
      log @getProxy()

    c.description = "Set properties on #{iface.name}"
    c.icon = 'book'

noflo = require 'noflo'
GLib = imports.gi.GLib
Gio = imports.gi.Gio
Lang = imports.lang

