AngularJS 自定义指令双向绑定 [英] AngularJS Custom Directive Two Way Binding

问题描述

如果我有一个没有模板的 AngularJS 指令，并且我希望它在当前范围内设置一个属性，那么最好的方法是什么?

If I have an AngularJS directive without a template and I want it to set a property on the current scope, what is the best way to do it?

例如，一个计算按钮点击次数的指令:

For example, a directive that counts button clicks:

<button twoway="counter">Click Me</button>
<p>Click Count: {{ counter }}</p>

使用将点击计数分配给双向属性中的表达式的指令:

With a directive that assigns the click count to the expression in the two way attribute:

.directive('twoway', [
'$parse',
  function($parse) {
    return {
      scope: false,
      link: function(scope, elem, attrs) {
        elem.on('click', function() {
          var current = scope.$eval(attrs.twoway) || 0;
          $parse(attrs.twoway).assign(scope, ++current);
          scope.$apply();
        });
      }
    };
  }
])

有没有更好的方法来做到这一点?从我读过的内容来看，一个孤立的范围会过大，但我需要一个子范围吗?除了使用 $parse 之外，是否有一种更简洁的方法来写回指令属性中定义的范围变量.我只是觉得我让这件事太难了.

Is there a better way to do this? From what I've read, an isolated scope would be overkill, but do I need a child scope? And is there a cleaner way to write back to a scope variable defined in the directive attribute other than using $parse. I just feel like I'm making this too difficult.

Full Plunker 此处.

Full Plunker here.

推荐答案

为什么隔离作用域是矫枉过正?它对这种事情非常有用:

Why is an isolate scope overkill? its pretty useful for exactly this kind of thing:

  scope: {
     "twoway": "=" // two way binding
  },

对于这个问题，这是一个非常惯用的角度解决方案，所以这就是我要坚持的.

This is a pretty idiomatic angular solution to this problem, so this is what I'd stick with.

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