devices.js

        return controllableSourceTypes.indexOf(this.type) > -1;
    }

/*
Current Selected Outputs: ItemSelection.getSelection()
var televisions = Devices.find({_id:{$in:ItemSelection.getSelection()}, type:Drivers.enums.types.Television},{fields:{name:1,rank:1})
var speakers    = Devices.find({_id:{$in:ItemSelection.getSelection()}, type:Drivers.enums.types.Speaker},{fields:{name:1,rank:1})

var tvSourceIds      = _.intersection(_.pluck(televisions,'sources'))
var speakerSourceIds = _.intersection(_.pluck(speakers,'sources'))

{
    'Audio/Video': _.intersection of tvSourceIds & speakerSourceIds
    'Video Only': tvSourceIds (sorted by rank) _.difference with (Audio/Video devices above)
    'Audio Only': speakerSourceIds (sorted by rank) _.difference with (Audio/Video devices above)
}

*/
    /**
     * Returns a nested hash of the audio/video sources that are available based
     * on the outputs selected.
     *
     * 1) If only audio devices are selected, this should return something like
     *  {
     *      name: 'Audio Only',
     *      sources: [
     *          {Device},   --- Devices.find({},{fields:{name:1, rank:1, state:1}}) -- Sort these devices by "rank"
     *          {Device},
     *          ...
     *      ]
     *  }
     *
     * 2) If only video devices are selected, this should return something like
     *  {
     *      name: 'Video Only',
     *      sources: [
     *          {Device},   --- Devices.find({},{fields:{name:1, rank:1, state:1}}) -- Sort these devices by "rank"
     *          {Device},
     *          ...
     *      ]
     *  }
     *
     * 3) If both video and audio devices are selected, this should return something like
     *  {
     *      name: 'Audio/Video',  // Devices that will affect a change on both televisions and speakers
     *      sources: [
     *          {Device},   --- Devices.find({},{fields:{name:1, rank:1, state:1}}) -- Sort these devices by "rank"
     *          {Device},
     *          ...
     *      ]
     *  }
     *  {
     *      name: 'Video Only', // Devices that will affect a change only on televisions
     *      sources: [
     *          {Device},   --- Devices.find({},{fields:{name:1, rank:1, state:1}}) -- Sort these devices by "rank"
     *          {Device},
     *          ...
     *      ]
     *  }
     *  {
     *      name: 'Audio Only', // Devices that will affect a change only on speakers
     *      sources: [
     *          {Device},   --- Devices.find({},{fields:{name:1, rank:1, state:1}}) -- Sort these devices by "rank"
     *          {Device},
     *          ...
     *      ]
     *  }
     */
    ,sourceGroups: function() {
        var sources, result = [];