Angular ngClick 阻止冒泡和默认行为

这其实是一个很简单的问题，如果你认真查看过Angular官方的API文档，本来不想记录的。但是这个问题不止一次的被人问起，所以今天在记录在这里。

在Angular中已经对一些ng事件如ngClick,ngBlur,ngCopy,ngCut,ngDblclick…中加入了一个变量叫做$event.

如ngClick在官方文档是这么描述的：

Expression to evaluate upon click. (Event object is available as $event)

在查看Angular代码ngEventDirs.js:

 var ngEventDirectives = {};
    forEach(
      'click dblclick mousedown mouseup mouseover mouseout mousemove mouseenter mouseleave keydown keyup keypress submit focus blur copy cut paste'.split(' '),
      function(name) {
        var directiveName = directiveNormalize('ng-' + name);
        ngEventDirectives[directiveName] = ['$parse', function($parse) {
          return {
            compile: function($element, attr) {
              var fn = $parse(attr[directiveName]);
              return function(scope, element, attr) {
                element.on(lowercase(name), function(event) {
                  scope.$apply(function() {
                    fn(scope, {$event:event});
                  });
                });
              };
            }
          };
        }];
      }
    );

   在上边代码我们可以得到两个信息：

Angular支持的event： click dblclick mousedown mouseup mouseover mouseout mousemove mouseenter mouseleave keydown keyup keypress submit focus blur copy cut paste
Angular在执行事件函数时候传入了一个名叫$event的常量，该常量即代表当前event对象，如果你在Angular之前引入了jQuery那么这就是jQuery的event.

所以我们可以利用event的stopPropagation来阻止事件的冒泡：如下代码：jsbin

html 代码:

<!DOCTYPE html>
    <html id="ng-app" ng-app="app">
    <head>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.1.5/angular.min.js"></script>
      <meta charset="utf-8">
      <title>JS Bin</title>
    </head>
    <body ng-controller="demo as d">
       <div ng-click="d.click('parent',$event)">
         given some text for click
         <hr>
         <input type="checkbox" ng-model="d.stopPropagation" />Stop Propagation ?
         <hr>
         <button type="button" ng-click="d.click('button',$event)">button</button>

       </div>
    </body>
    </html>

js 代码:

angular.module("app",[])
.controller("demo",[function(){
  var vm = this;

  vm.click = function(name,$event){
    console.log(name +" -----called");
    if(vm.stopPropagation){
      $event.stopPropagation();
    }
  };

  return vm;
}]);

可以在jsbin](http://jsbin.com/delow/3/watch?html,js,output)查看效果。

首先打开你的控制台，然在没选中Stop Propagation的情况下点击button你将会看见两条log记录，相反选中后则只会出现button的log信息。

希望大家已经明白了，不要再问这类问题了。

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