Angular ngClick 阻止冒泡和默認行為

這其實是一個很簡單的問題，如果你認真查看過Angular官方的API文檔，本來不想記錄的。但是這個問題不止一次的被人問起，所以今天在記錄在這里。

在Angular中已經對一些ng事件如ngClick,ngBlur,ngCopy,ngCut,ngDblclick…中加入了一個變量叫做$event.

如ngClick在官方文檔是這么描述的：

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

在查看Angular代碼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});
                  });
                });
              };
            }
          };
        }];
      }
    );

   在上邊代碼我們可以得到兩個信息：

Angular支持的event： click dblclick mousedown mouseup mouseover mouseout mousemove mouseenter mouseleave keydown keyup keypress submit focus blur copy cut paste
Angular在執行事件函數時候傳入了一個名叫$event的常量，該常量即代表當前event對象，如果你在Angular之前引入了jQuery那么這就是jQuery的event.

所以我們可以利用event的stopPropagation來阻止事件的冒泡：如下代碼：jsbin

html 代碼:

<!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 代碼:

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。

首先打開你的控制台，然在沒選中Stop Propagation的情況下點擊button你將會看見兩條log記錄，相反選中后則只會出現button的log信息。

希望大家已經明白了，不要再問這類問題了。

Angular ngClick 阻止冒泡和默認行為

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