Angularjs - $ $范围破坏不会删除观察家 [英] Angularjs - $scope.$destroy doesn't remove watchers

问题描述

我试图找出如何创建自己的一次性绑定，为Angularjs＆LT; = 1.2。
我发现这个回答，描述了如何创建自己的bindOnce指令。我确实看到使用以下指令时：

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。 但是上，我可以看到$$观察家还亮着。看看下面的 JSBin - 运行评论观察家计数在控制台上code就会发现，在观察家还活着。

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.

修改：出于某种原因，使用具有角1.3相同的指令时，观察者计数mod改为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

使用清除函数删除观察家：

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个简单的绑定一次：

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，以供参考迁移指南找到突破的变化：

Use the migration guide for reference to find breaking changes:

参考

• testabilityPatch.js

角mocks.js

AngularJS开发指南：从previous版本迁移

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