Another issue after AngularFire 0.5.0 update - calculation returns NaN

Question

I'm more and more disappointed with the angularFire 0.5.0, because nothing works correctly anymore. After I was able to fix the remove of a single item with help of you, I ran into another issue.

Each single item consists of a date, description and price. Before I updated, I was able to calculate the total of all prices and return it on the page. Now it just says NaN or Null. I was already trying to figure out why, but both values (earning.price, $scope.totalEarning) in the calculation are numbers. I don't get it. Does the new angular fire do anything? I'm trying to fix it since a while and just can't. I would be really, if somebody could figure it out. Probably I'm just not seeing it and it's a pretty dumb issue.

See it on plunkr: http://embed.plnkr.co/jb1iWOcjcm0alFchmzOH/preview

Here is the code:

$scope.addEarning = function() {
    $scope.earnings.$add({date:$scope.FormEarningDate, description:$scope.FormEarningDescription, price:$scope.FormEarningPrice});    
    $scope.FormEarningDate = '';
    $scope.FormEarningDescription = '';
    $scope.FormEarningPrice = '';
    $scope.updateEarning();
}

$scope.updateEarning = function() {
    $scope.totalEarning = 0;
    angular.forEach($scope.earnings, function (earning) {
        price = parseFloat(earning.price)
        $scope.totalEarning += price;
        $log.log(typeof $scope.totalEarning);
    })
    $scope.totalBalance = $scope.totalEarning - $scope.totalCost;
}

And the html:

<form for="Profit" class="form-inline" style="margin-bottom: 20px" ng-submit="addEarning()">
    <div class="form-group">
        <div class="col-sm-3">
            <input type="date" name="idate" ng-model="FormEarningDate" class="form-control" id="idate" placeholder="Date">
    </div>
    <div class="col-sm-5">
        <input type="text" name="idesc" ng-model="FormEarningDescription" required class="form-control" id="idesc" placeholder="Description">
    </div>
    <div class="col-sm-2">
        <input type="text" name="iprice" ng-model="FormEarningPrice" required class="form-control" id="iprice" placeholder="Amount">
    </div>
</div>




<tr ng-repeat="earning in earnings | orderByPriority | orderBy : 'date'">
    <td>{{earning.date}}</td>
    <td>{{earning.description}}</td>
    <td>{{earning.price}} €</td>
    <td><button class="btn btn-danger" ng-click="earnings.$remove(earning.$id)">Löschen</button></td>
</tr>
<tr>
    <td colspan="2"></td>
    <td><strong>Total:</strong> {{totalEarning}} €</td>
    <td></td>
</tr>

Answer 1

Updated Answer

There are several things you are doing incorrectly. As stated in my original answer, you need to iterate over the keys from Firebase, not the firebase object itself. Additionally, you need to ensure all updates happen after Firebase has updated (via an $on('change', ...) event handler) and within the AngularJS lifecycle (accomplished below using $timeout).

var app = angular.module('balance', ['firebase']);
app.controller('BalanceCtrl', function($scope, $log, $http, $timeout, $firebase) {
  $scope.earnings = $firebase(new Firebase('https://dgdemo.firebaseio.com/Earnings'));

  $scope.totalBalance = 'Nothing yet.';
  $scope.totalEarning = 0;
  $scope.totalCost = 0;

  $scope.updateEarning = function() {
    $scope.totalEarning = 0;
    angular.forEach($scope.earnings.$getIndex(), function (id) {
      var earning = $scope.earnings[id];
      $scope.totalEarning += parseFloat(earning.price);
    });
    $scope.totalBalance = $scope.totalEarning - $scope.totalCost;
  };
  // Ensure any call to updateCallback will execute within the AngularJS lifecycle.
  var updateCallback = angular.bind(null, $timeout, $scope.updateEarning);

  $scope.addEarning = function() {
    var earning = $scope.earnings.$add({
      date: $scope.FormEarningDate,
      description: $scope.FormEarningDescription,
      price: $scope.FormEarningPrice
    });
    $scope.FormEarningDate = '';
    $scope.FormEarningDescription = '';
    $scope.FormEarningPrice = '';
  };

  $scope.earnings.$on('change', updateCallback);
});

Original Answer

This is because angular.forEach is iterating over all properties of the $scope.earnings object (which is a Firebase object). What you want to do is iterate over the individual items.

$scope.updateEarning = function() {
  $scope.totalEarning = 0;
  angular.forEach($scope.earnings.$getIndex(), function (id) {
    var earning = $scope.earnings[id];
    $scope.totalEarning += parseFloat(earning.price);
  });
  $scope.totalBalance = $scope.totalEarning - $scope.totalCost;
}