AngularJS: Summing nested objects from multiple objects - angularjs

Question

Based in the following table I need to get the total of all subtotals.
I have tried to use the same sumByKey filter but I does't work.
Plus, the sum of all subtotals must be based on the result of the filter, it means, If we have two results (two categories) the sum of subtotals must be based on those objects. Any idea?
html
<table border="1">
<thead>
<tr>
<th>#</th>
<th>Category</th>
<th>Products with quantities</th>
<th>Subtotal of quantities</th>
</tr>
</thead>
<tbody align="center">
<tr data-ng-repeat="category in categories | filter:search">
<td>{{$index+1}}</td>
<td>{{category.name}}</td>
<td>{{category.products}}</td>
<td>{{category.products | sumByKey:'quantity'}}</td>
</tr>
</tbody>
<thead align="right">
<tr>
<td colspan="3"><strong>Total</strong></td>
<td></td>
</tr>
</thead>
</table>
angularjs
var app = angular.module("app", []);
app.controller("controllerApp", function($scope, $http){
$http.get("categories.json").success(function(data) {
$scope.categories = data;
});
});
app.filter('sumByKey', function () {
return function (data, key) {
if (typeof (data) === 'undefined' || typeof (key) === 'undefined') {
return 0;
}
var sum = 0;
for (var i = data.length - 1; i >= 0; i--) {
sum += parseInt(data[i][key]);
}
return sum;
}
});

Answer 1

May not be Angular solution. But you can also get total by pure JavaScript.
By keeping a total $scope varaible like this inside your controller
$scope.total = getTotal(data);
function getTotal(data){
var total = 0;
data.forEach(function(item){
item.products.forEach(function(product){
total += product.quantity;
})
});
return total;
}
Here is the updated Plunker.

Answer 2

It can be done with angular also.
Example : http://plnkr.co/edit/zhTtoOjW7J1oumktlvFP?p=preview
HTML:
<table border="1">
<thead>
<tr>
<th>#</th>
<th>Category</th>
<th>Products with quantities</th>
<th>Subtotal of quantities</th>
</tr>
</thead>
<tbody align="center">
<tr data-ng-repeat="category in filterValues=(categories | filter:search)">
<td>{{$index+1}}</td>
<td>{{category.name}}</td>
<td>{{category.products}}</td>
<td>{{category.products | sumByKey:'quantity'}}</td>
</tr>
</tbody>
<thead align="right">
<tr>
<td colspan="3"><strong>Total</strong></td>
<td>{{filterValues | sumOfValue:'quantity'}}</td>
</tr>
</thead>
</table>
JS:
// Code goes here
var app = angular.module("app", []);
app.controller("controllerApp", function($scope, $http) {
$http.get("categories.json").success(function(data) {
$scope.categories = data;
});
});
app.filter('sumByKey', function() {
return function(data, key) {
if (typeof(data) === 'undefined' || typeof(key) === 'undefined') {
return 0;
}
var sum = 0;
for (var i = data.length - 1; i >= 0; i--) {
sum += parseInt(data[i][key]);
}
return sum;
}
});
app.filter('sumOfValue', function() {
return function(data, key) {
if (angular.isUndefined(data) || angular.isUndefined(key)) {
return 0;
}
var sum = 0;
for (var i = 0; i < data.length; i++) {
var value = data[i];
if (!angular.isUndefined(value)) {
for (var j = 0; j < value.products.length; j++) {
sum += parseInt(value.products[j][key]);
}
}
}
return sum;
}
});