Creating dynamic invoice with angularjs - angularjs

Question

I try to create a dynamic invoice, i have quantity and price column, and then i get total Value Of Products, so when i change value of quantity, price and total value should be changed, i find a way to change price but total value does not work:
<div class="container" ng-controller="OrderController" ng-init="quantity=1">
<div id="order-detail-content" class=" row">
<table id="cart_summary">
<thead>
<tr>
<th>Total</th>
<th> </th>
<th>Qty</th>
<th>Unit price</th>
<th>Availability</th>
<th>Description</th>
<th>Product</th>
</tr>
</thead>
<tfoot>
<tr class="cart_total_price">
<td colspan="2" class="price" id="total_product">{{totalValueOfProducts}}</td>
<td colspan="3" class="text-right">Total</td>
<td rowspan="4" colspan="3" id="cart_voucher" class="cart_voucher"></td>
</tr>
</tfoot>
<tbody>
<tr ng-repeat="order in Orders track by $index" >
<td class="cart_total" data-title="Total">
<span class="price" id="total_product_price_3_13_0">
{{order.Price * quantity}}
</span>
</td>
<td >
<input size="2" ng-model="quantity" type="text" value="1" name="quantity_3_13_0_0">
</td>
<td>
<ul class="price text-right" id="product_price_3_13_0">
<li ng-model="order.Price" class="price"> {{order.Price}}</li>
</ul>
</td>
<td class="cart_description">
<p style="color:black" class="product-name">{{order.ProductName}}</p>
<hr />
<small style="color:black" class="cart_ref">{{order.ProductDescription}}</small>
</td>
<td class="cart_product">
<img ng-src="" alt="Printed Dress" width="98" height="98">
</td>
</tr>
</tbody>
</table>
</div> <!-- end order-detail-content -->
and in controller i define $watch on quantity :
<script>
app.controller('OrderController', function ($scope, $http) {
$scope.Orders = {};
$scope.GetOrders = function () {
$http.get('/Order/GetAllOrders').success(function (response) {
$scope.Orders = response;
//debugger;
GetTotalValueOfProducts(response);
});
}
$scope.GetOrders();
GetTotalValueOfProducts = function (response) {
//debugger;
$scope.totalValueOfProducts = 0;
for (var i = 0; i < response.length; i++) {
$scope.totalValueOfProducts += response[i].Price * $scope.quantity;
}
}
$scope.$watch('quantity', function () {
debugger;
$scope.GetOrders();
});
});
</script>
when i changed value of quantity, the value of totalValueOfProducts was not changed!why $watch did not work? what is the problem?

Answer 1

'quantity' needs to be in the $scope for the binding to take place
on a separate note, it would be better to move all data (orders, quantity etc) into a service, it would better adhere to angular's MVC paradigm