AngularJS ng-bind与函数

Question

我想显示“附件”部分的表格格式。我有查询和结果数据。两者都有一个共同的列attachmentTypeId。我想显示基于ID的附件类别描述。在ng- bind我尝试过的尝试中，它没有用。

我在中使用一个函数ng-bind，希望方法错误，期望该方法有一个替代方案。

该attachmentLookup包含attachmentDesc，attachmentTypeId

  $scope.attachmentLookup = [{
    "attachmentDesc": "Category One",
    "attachmentTypeId": "1"
  }, {
    "attachmentDesc": "Category Two",
    "attachmentTypeId": "2"
  }, {
    "attachmentDesc": "Category Three",
    "attachmentTypeId": "3"
  }, {
    "attachmentDesc": "Category Four",
    "attachmentTypeId": "4"
  }, {
    "attachmentDesc": "Category Five",
    "attachmentTypeId": "5"
  }];

和attachmentDetails来自数据库的数据一样，

  $scope.attachmentDetails = [{
    "attachmentId": "001",
    "fileName": "File Name 001",
    "attachmentTypeId": "1"
  }, {
    "attachmentId": "003",
    "fileName": "File Name 003",
    "attachmentTypeId": "2"
  }, {
    "attachmentId": "005",
    "fileName": "File Name 005",
    "attachmentTypeId": "3"
  }, {
    "attachmentId": "007",
    "fileName": "File Name 007",
    "attachmentTypeId": "1"
  }, {
    "attachmentId": "009",
    "fileName": "File Name 009",
    "attachmentTypeId": "2"
  }, {
    "attachmentId": "011",
    "fileName": "File Name 011",
    "attachmentTypeId": "3"
  }];

HTML代码为

<table>
  <thead>
    <tr>
      <th>File Name</th>
      <th>|</th>
      <th>Category</th>
    </tr>
  </thead>
  <tbody>
    <tr ng-repeat="attachment in attachmentDetails">
      <td> <span ng-bind="attachment.fileName"></span>
      </td>
      <td>|</td>
      <td> <span ng-bind="getCatgoryName(attachment.attachmentTypeId)"></span>
      </td>
    </tr>
  </tbody>
</table>

getCatgoryName控制器的代码是

$scope.getCatgoryName = function (attachmentTypeId) {
    angular.forEach($scope.attachmentLookup, function (attachemnt) {
        if (attachemnt.attachmentTypeId === attachmentTypeId)
            return attachemnt.attachmentDesc;
    });
};

样本柱塞：http
://plnkr.co/edit/dZy5gW4q9CxWF2NszXYc

Answer 1

括号是否经过脏检查，因此每个函数都会被调用$digest。

这ng-bind是一条指令，它将在传递给的内容上使用观察者ng-bind。

因此，ng-bind仅在传递的变量或值确实发生更改时才适用。

使用函数时，您没有传递变量，因此不会为每个变量触发$digest。

因此，最好在函数调用中使用方括号。

我在这里更新了插件：http
://plnkr.co/edit/LHC2IZ0Qk9LOOYsjrjaf?p=preview

我在这里更改了HTML：

<tr ng-repeat="a in attachmentDetails">
    <td> <span>{{a.fileName}}</span></td>
    <td>|</td>
    <td> {{ getCatgoryName(a.attachmentTypeId) }}</td>
</tr>

该功能也已修改：

  $scope.getCatgoryName = function(attachmentTypeId) {
    var desc = "";
    angular.forEach($scope.attachmentLookup, function(attachemnt) {
      if (parseInt(attachemnt.attachmentTypeId) == attachmentTypeId)
        desc = attachemnt.attachmentDesc;
    });

    return desc;
  };