运行到无限循环消化，同时结合到具有$ HTTP内部功能 [英] Running into infinite digest cycle while binding to function that has $http inside

问题描述

我需要生成HTTP链接 A 标记。出于这个原因，我把 HTML 行

I need to generate http link for a tag. For that reason I put in html line

<a href="{{getLink(url)}}">My link</a>

在控制器它定义为：

$scope.getLink = function(inputUrl){

    $http.get(inputUrl).success(function(data){/*.....*/});

}

为什么AngularJS无限循环结束了？什么是正确的设计？

Why AngularJS ends up in infinite cycle? What is the right design?

推荐答案

作为另一个答案解释，看了前pressions是在每一个消化和产生的价值进行评估时相比，他们的previous价值 - 脏检查。如果有变化，摘要的另一迭代开始，因为在一个值的变化可能会导致在另一变化

As explained in another answer, watched expressions are evaluated on every digest and the resulting value is compared to their previous value - dirty checking. If there is a change, another iteration of the digest starts because a change in one value might cause a change in another.

如果有一个循环依赖（包括一个圆，即相同的前pression是不同的每次），它会导致一个无限循环的角度经过10次迭代停止。

If there is a circular dependency (including, the circle of one, i.e. the same expression is different every time), it results in an infinite loop that Angular stops after 10 iterations.

具体来说，您的 getLink 函数的返回值是一种承诺，并在承诺角绑定不会等待（的$ HTTP返回值）。

Specifically, your getLink function's return value is a promise (the return value of $http), and Angular bindings do not "wait" on a promise.

您想要做的是踢启动 $ HTTP 呼叫，并在其分配处理程序的返回值将被绑定到<$ C $一个ViewModel财产C>＆LT; A＆GT; ：

What you want to do is to kick start the $http call and in its handler assign the return value to a ViewModel property that would be bound to <a>:

function getLink(){
  $http.get(inputUrl)
      .success(function(data){
         $scope.url = data.data;
      });
}

您可以致电 getLink ，例如，当你的控制器运行。

You can call getLink, for example, when your controller runs.

在查看刚刚绑定网​​址来的 NG-HREF （未的href ）属性：

In the View you just bind url to ng-href (not href) attribute:

<a ng-href="url">My Link</a>

这篇关于运行到无限循环消化，同时结合到具有$ HTTP内部功能的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！