formatCollection.js

/**
 * This is an example of the results from requesting
 * a user stream from Soundcloud's API.
 *
 * The objects in the collection are a mix of tracks and playlists
 * sorted by date.
 * 
 * @type {Array}
 */
var items = [
  // this is a track item
  {
    "type": "track",
    "created_at": "2014/06/16 22:29:09 +0000",
    "track": {
      "id": 154591682,
      "created_at": "2014/06/16 11:33:38 +0000",
      "user_id": 46059856,
    },
    "playlist": null
  },

  // this a playlist
  {
    "type": "playlist_repost",
    "track": null,
    "playlist": {
      "id": 40585650,
      "created_at": "2014/06/20 16:22:58 +0000",
      "permalink_url": "http://soundcloud.com/rudeluv/sets/coders-special",
      "user": {
        "id": 315279,
      },
      "tracks": [{
        // collection of track objects
      }]
    }
  }
];

/**
 * I'm using Angular's $q service to return a promise in the Soundcloud.get function
 * This is the function that is in the .this() after Soundcloud.get is called.
 *
 * I need to take the playlist and track fields up one level and add a 'reposted' boolean
 * property to the object.
 * 
 * @param  {[type]} items
 * @return {[type]}
 */
function makeStream() {
    var new_item;
    var tracks = [];
    var playlists = [];
    
    _.each(items, function(item) {
      new_item.is_repost = (item.type.slice(-6) === 'repost');

      if (item.type === 'playlist' || item.type === 'playlist_repost') {
        new_item = item.playlist;
        playlists.push(new_item);
      } else {
        new_item = item.track;
        tracks.push(new_item);
      }
    });
    
    return {'playlists': playlists, 'tracks':tracks};
  }