如何计算ng-repeat中的行总和？

Question

我有一个稍微不同的要求，请您在标记为重复之前通读一遍。举个例子：

<table ng:init="stuff={items:[{description:'gadget', cost:99,date:'jan3'},{description:'thing', cost:101,date:'july6'},{description:'thing', cost:101,date:'jan3'} ]}">
    <tr>
        <th>Description</th>
        <th>Cost</th>
    </tr>

    <tr ng:repeat="item in stuff.items|filter">   /*only filtered item grouped by date*/    
        <td>{{item.description}}</td>
        <td ng-bind='item.cost'>{{item.cost}}</td>
    </tr>

    <tr>
        <td></td>
        <td>{{total}}</td>   /*cost of items grouped by date jan3*/
    </tr>
</table>

如何计算按项目分组的总成本？angular 中是否有任何数据属性，我可以在其中添加分组项目的成本，然后再次为下一个分组项目重新初始化它？

Answer 1

您可以创建自己的自定义过滤器，它将接受数组 return 您所有项目的总成本。

标记

<tr ng:repeat="item in filteredData = (stuff.items|filter)">
    <td>{{item.description}}</td>
    <td ng-bind='item.cost'>{{item.cost}}</td>
</tr>
<tr>
    <td></td>
    <td>{{filteredData| total}}</td>   /*cost of items grouped by date jan3*/
</tr>

代码

app.filter('total', function(){
  return function(array){
    var total = 0;
    angular.forEach(array, function(value, index){
       if(!isNaN(value.cost))
        total = total + parseFloat(value.cost);
    })
    return total;
  }
})

Answer 2

Angular 1.3 添加了 create an alias to your ng-repeat 的功能，与过滤器一起使用时非常有用。

variable in expression as alias_expression – You can also provide an optional alias expression which will then store the intermediate results of the repeater after the filters have been applied. Typically this is used to render a special message when a filter is active on the repeater, but the filtered result set is empty.

For example: item in items | filter:x as results will store the fragment of the repeated items as results, but only after the items have been processed through the filter.

因此，您可以使用此 as alias_expression 对列表的筛选子集执行计算。即：

<tr ng-repeat="item in stuff.items|filter as filteredStuff">
  {{filteredStuff.length}}
  {{calculateTotal(filteredStuff)}}
</tr>

在控制器中：

$scope.calculateTotal = function(filteredArray){
    var total = 0;
    angular.forEach(filteredArray, function(item){
        total += item.cost;
    });
    return total;
};

如何计算ng-repeat中的行总和？

How to calculate sum of rows in ng-repeat?

javascript

angularjs

angularjs-ng-repeat

ng-repeat

angularjs-filter