title: AngularJS Calculating product prices with multiple select options
body: <p>Summary:</p>
  
  <p>Users should be choosing their desired products in a form environment. Every product has a core price and multiple additional options available which change the price when selected.</p>
  
  <p>Products and options are shown in two SELECT fields which are getting populated like this:</p>
  
  <pre><code>$scope.products = [
  {
      name:'Product A',
      cost:5,
      options: [{name:"Option 1", value:10}]
  },
  
  {
      name:'Product B',
      cost:10,
      options: [{name:"Option 1", value:10},{name:"Option 2", value:15}]
  }
  ];
  
  $scope.cart = {
      items: [{            
          qty: 1,
      }]
  };
  </code></pre>
  
  <p>and</p>
  
  <pre><code>&lt;tr ng:repeat="item in cart.items"&gt;
    &lt;td&gt;
      &lt;div class="type-select"&gt;
        &lt;select ng-model="item.product" ng-options="p.name for p in products"&gt;&lt;/select&gt;
      &lt;/div&gt;      
    &lt;/td&gt;
    &lt;td&gt;
      &lt;div class="type-select"&gt;
        &lt;select ng-model="item.option" ng-options="o for o in item.product.options.name" ng- disabled="!checked"&gt;
      &lt;/div&gt;         
    &lt;/td&gt;    
    &lt;td&gt;
      &lt;input ng:model="item.qty" value="1" size="4" ng:required="" ng:validate="integer" class="ng-pristine ng-valid ng-valid-required input-mini"&gt;
    &lt;/td&gt;
    &lt;td&gt;
       {{calculate()}}
    &lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <ol>
  <li><strike>The options select stays empty. Why?</strike></li>
  <li>How can i calculate this the angular way? (There will be multiple lines of product possible)</li>
  </ol>