如何在AngularJS中观察自定义事件?

Val*_*sin 14 javascript angularjs angularjs-directive

简单的例子:我有一个textarea并希望为它提供额外的行为:在enterkey 上执行某些操作并转到下一行shift + enter

我想我应该提供额外的指令来添加该行为.我做到了这一点:http://jsbin.com/oruvuy/1/edit

PS一个hackie的东西对我来说似乎很奇怪:我$digest()手动调用.好吗?有什么想法吗?

JS:

angular.module('Chat', [])
  .directive('enterSubmit', function () {
    return {
      restrict: 'A',
      link: function (scope, element, attrs) {
        var submit;

        $(element).on({
          keydown: function (e) {
            submit = false;

            if (e.which === 13 && !e.shiftKey) {
              submit = true;
              e.preventDefault();
            }
          },

          keyup: function () {
            if (submit) {
              scope.$eval( attrs.enterSubmit );

              // flush model changes manually
              scope.$digest();
            }
          }
        });
      }
    };
  });

function ChatCtrl($scope) {
  $scope.messages = [{
    text: 'Sample Message',
    datetime: new Date()
  }];

  $scope.add = function () {
    $scope.messages.push({
      text: $scope.message,
      datetime: new Date()
    });
    $scope.message = '';
  };

  $scope.message = '';
}
Run Code Online (Sandbox Code Playgroud)
<body ng-controller="ChatCtrl">

  <h1>Leave message:</h1>
  <form>
    <div class='hint'>Click &lt;Enter&gt; to submit :)</div>
    <textarea
      cols="30"
      rows="5"
      ng-model="message"
      enter-submit='add()'
    ></textarea>
    <br />
    <button type="submit" ng-click="add()">Send message!</button>
  </form>

  <h3>Messages list:</h3>
  <table>
    <tr>
      <th>Text</th>
      <th>Date</th>
    </tr>
    <tr ng-repeat="message in messages">
      <td class='text'>{{message.text}}</td>
      <td class='date'>{{message.datetime | date:"HH:mm:ss"}}</td>
    </tr>
  </table>

</body>
Run Code Online (Sandbox Code Playgroud)

但这样做是否正确?

jin*_*man 12

是的,指令的链接功能中的绑定事件正是您想要做的.

调用$ digest并不是hacky - 你的例子中的消息被添加到模型中keyup,Angular不会消除这些更改,直到有人告诉它.它实际上会在下一个消化keydown,但由于你需要在你之后发生$ digest keyup,你必须手动调用它.