Angularjs注意父范围的变化 [英] Angularjs watch for change in parent scope

问题描述

我正在写一个指令，我需要观察更改的父作用域。不确定我是否这样做是首选方式，但它不能使用以下代码：

I'm writing a directive and I need to watch the parent scope for a change. Not sure if I'm doing this the preferred way, but its not working with the following code:

  scope.$watch(scope.$parent.data.overlaytype,function() {
    console.log("Change Detected...");
  })

它记录了窗口加载，但即使更改了overlaytype也不会再次登录。

This it logged on window load, but never again, even when overlaytype is changed.

我怎么能观看 overlaytype 进行更改？

How can I watch overlaytype for a change?

编辑：这是整个指令。我不完全确定为什么我会得到一个子范围

here is the entire Directive. Not entirely sure why I'm getting a child scope

/* Center overlays vertically directive */
aw.directive('center',function($window){
  return {
    restrict : "A",
    link : function(scope,elem,attrs){

      var resize = function() {
        var winHeight = $window.innerHeight - 90,
            overlayHeight = elem[0].offsetHeight,
            diff = (winHeight - overlayHeight) / 2;
            elem.css('top',diff+"px");
      };

      var watchForChange = function() {
        return scope.$parent.data.overlaytype;
      }
      scope.$watch(watchForChange,function() {
        $window.setTimeout(function() {
          resize();
        }, 1);
      })

      angular.element($window).bind('resize',function(e){
        console.log(scope.$parent.data.overlaytype)
        resize();
      });
    }
  };
});

推荐答案

你应该拥有数据子范围的属性，范围使用父范围和子范围之间的原型继承。

You should have the data property on your child scope, scopes use prototypal inheritance between parent and child scopes.

此外， $ watch 方法所期望的第一个参数是要评估的表达式或函数，而不是变量的值。所以你应该发送它。

Also, the first argument the $watch method expects is an expression or a function to evaluate and not a value from a variable., So you should send that instead.

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