喷油器返回未定义的值? [英] Injector returns undefined value?

问题描述

1. 我正在尝试从旧版代码中获取服务，并遇到一个奇怪的错误，其中injector()返回未定义:

选中此 plnkr

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1. 此外，我正在尝试将新的属性值重新设置为服务，是否可以在不使用watch的情况下将其反映到作用域?

非常感谢您，任何指针或建议都将受到赞赏.

Thank you very much, any pointer or suggestion is much appreciated.

推荐答案

您正在尝试在DOM构建之前获取元素.与在$(document ).ready()外部运行javascript基本上是相同的问题.因此，此行没有要获取的元素:

You're trying to get the element before the DOM has been constructed. It's basically the same issue as running javascript outside of a $(document ).ready(). So this line has no element to get:

var elem = angular.element($('#myCtr'));

另外，顺便说一句，代替上面的jQuery，另一个用于执行上述操作的Angular选项是:

Also, by the way, instead of using jQuery, another Angular option for doing the above is:

var elem = angular.element(document.querySelector('#myCtr'))

Angular提供了与$(document ).ready()等效的名称，称为angular.element(document).ready()，我们可以使用它.

Angular provides an equivalent to $(document ).ready() called angular.element(document).ready() which we can use.

但是您还需要获取scope并在scope.$apply()内执行更改，以便Angular知道您已更改了应注意的内容.

But you'll also need to grab scope and execute your change within a scope.$apply() so that Angular is aware that you've changed something that it should be aware of.

将两者结合起来:

angular.element(document).ready(function () {

   var elem = angular.element($('#myCtr'));
   //get the injector.
   var injector = elem.injector();   

   scope= elem.scope();

   scope.$apply(function() {
      injector.get('cartFactory').cart.quantity = 1;
   });
});

更新了plnkr

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