Angularjs - $scope.$destroy 不会删除观察者

问题描述

我想弄清楚如何为 Angularjs <= 1.2 创建我自己的一次性绑定".我找到了这个 answer，描述了如何创建自己的 bindOnce 指令.在使用以下指令时，我确实看到了这一点:

I am trying to figure out how to create my own "one time binding", for Angularjs <= 1.2.I found this answer, describing how to create your own bindOnce directive. I do see that when using the following directive:

    app.directive('bindOnce', function() {
    return {
            scope: true,
            link: function( $scope ) {
                setTimeout(function() {
                    $scope.$destroy();
                }, 0);
            }
        }
    });

数据绑定一次.但是，我可以看到 $$watchers 仍在运行.看看下面的JSBin - 运行评论的观察者控制台上的计数代码将显示观察者还活着.

Data is binded once. But, I can see that the $$watchers is still on. Take a look at the following JSBin - running the commented watcher count code on the console will reveal that the watchers are still alive.

EDIT:由于某种原因，当使用与 angular 1.3 相同的指令时，观察者计数 dod 变为 0！！！

EDIT: for some reason, when using the same directive with angular 1.3, the watcher count dod changed to be 0!!!

推荐答案

使用 cleanup 函数移除观察者:

Use the cleanup function to remove watchers:

function cleanup(element)
  {
  element.off().removeData();

  var injector = currentSpec.$injector;

  element.$injector = null;

  // clean up jquery's fragment cache
  angular.forEach(angular.element.fragments, function(val, key) {
    delete angular.element.fragments[key];
  });

  angular.forEach(angular.callbacks, function(val, key)
    {
    delete angular.callbacks[key];
    });

  angular.callbacks.counter = 0;
  }

使用自毁服务作为一次简单的绑定:

Use a self-destructing service as a simple bind once:

function onetime()
  {
  /*...*/
  onetime = Function;
  }

angular.module('myApp').constant('bindonce', onetime);

angular.module('myApp').controller('foo', function($bindonce){
  this.$inject = '$bindonce';
  $scope.mybind = $bindonce();
}

使用迁移指南作为参考以查找重大更改:

Use the migration guide for reference to find breaking changes:

参考资料

• testabilityPatch.js

angular-mocks.js

AngularJS 开发人员指南:从以前的版本迁移

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