Async event builder for Gatorade Showcase

api.build_event.js

  build_event: function buildEvent(id, callback){
    var mungeData
      , responses = []
      , path = '/events/' + id
      , workers = [
          '',
          '/stats',
          '/roster',
          '/votes',
          '/attendees'
        ]
    ;//var

    //
    // Takes the responses in the response array and
    // munges them together. This function is only executed
    // after it is called X number of times (X being the
    // number of workers) to ensure that all responses
    // have been recieved
    //
    mungeData = _.after(workers.length, function(){

      //
      // Check all the responses for errors
      //
      if(_.any(responses, hasError)) return;

      function hasError(res){
        var data = res.response;
        if(res.status != 200 || res.status != 201 ||  || !data || data.error || data == "Invalid signed request"){
          showError("An error occured getting your event.");
          app.router.navigate('dashboard', {'trigger': true});
          return true;
        }
        return false;
      }

      //
      // Responses are stored in an array
      // in the order they were called
      //
      var root      = responses[0].response
        , stats     = responses[1].response
        , rosters   = responses[2].response
        , votes     = responses[3].response
        , attendees = responses[4].response
      ;//var

      //
      // Combine the responses and pass them back
      // to the callback
      //
      callback(stitchParts(app.user.id, root, stats, rosters, votes, attendees));
    });

    //
    // Make ajax calls in parallel for each of the
    // worker endpoints
    //
    _.each(workers, function(endpoint, idx){
      api.get(path + endpoint + '.json', {'signed_req':app.signed_req}, collector(idx))
    });

    //
    // Collector is used to gather responses in the
    // order they were requested
    // It also executes mungedata after each response is
    // returned
    //
    function collector(id){ return function(res){ responses[id] = res; mungeData() } }

    function stitchParts(fbUserId, root, stats, rosters, votes, attendees) {
      root.mvp_pick  = votes.my_mvp;
      root.team_pick = votes.my_team;

      var teams = {}
      teams[root.team.id]          = root.team;
      teams[root.opponent_team.id] = root.opponent_team;

      /* this would easily extend to mulitple teams */
      for (var teamId in teams) {
        var team    = teams[teamId]
          , roster  = rosters[teamId] || {};

        team.num_votes        = votes.teams[teamId] || 0;
        team.attendees        = attendees[teamId]   || [];
        team.roster           = roster.players      || [];
        team.supporters       = roster.supporters   || [];
        team.supporter_count  = roster.supporters.length;
        team.user_role        = null;

        /* is the user a player on this team? */
        for (var n = team.roster.length; n --; )
          if (fbUserId === team.roster[n].fb_user_id)
            team.user_role = 'player';

        /* is the user a supporter of this team? */
        for (var n = team.supporters.length; n --; )
          if (fbUserId === team.supporters[n].fb_user_id)
            team.user_role = 'supporter';

        delete team.supporters;

        for (var n = team.roster.length; n --; ) {
          var player = team.roster[n];
          player.id           = player.team_membership_id;
          player.mvp_votes    = votes.players[player.id]  || 0;
          player.stats        = stats[player.id]          || {};
          player.stat_source  = player.stats.stat_source;
          delete player.stats.stat_source;
        }
      }

      return root;
    }
  },