Hmm, bacon

gistfile1.js

      var usersStream = Bacon.interval(3000)
                .filter(function(){ return this.state.mode === "users" }.bind(this))
                .flatMapLatest(function(){
                    var store = this.state.selectedStore;
                    return Bacon.fromPromise( $.ajax({
                      type: 'GET',
                      url: '/users/',
                      data: {store_id: store.id}
                    }) );
                }.bind(this))
                .map(function(resp){ return resp.data });


                usersStream.filter(function(users){
                  var currentUsers = this.state.users;
                  var somethingChanged = false;

                  var oldIds = _.map(currentUsers, function(u){ return u.id });
                  var newIds = _.map(users, function(u){ return u.id });
                  //_.difference([1, 2, 3, 4, 5], [5, 2, 10]);
                  //=> [1, 3, 4]
                  /* Find those missing (left) */
                  var missing = _.difference(newIds, oldIds);
                  console.log("missing: "+missing);
                  /* Find those added (enter) */
                  var added = _.difference(oldIds, newIds);
                  console.log("added: "+added);
                  /* Find state changes */
                  var same = _.intersection(oldIds, newIds);
                  var changed = _.filter(same, function(id){
                    var currentUser = currentUsers[_.find(
                    var candidateUser = users[_.find(curIds, {id:id})]
                  });
                  console.log("same: "+same);
                  console.log(missing.length);
                  return somethingChanged;
                }.bind(this))
                .log();