将`this`传递给ng-click中的函数会暴露什么？

Question

Assume we have a button with a ng-click directive.It calls a function passing this as an argument. Upon inspection, the type of the parameter passed is found to be an object.But neither does it have any of the element properties , nor is it a jQuery selector.

What exactly gets passed ?

Answer 1

ngClick and similar directives are executed in context of the current scope. So this refers scope object.

If you don't have ngRepeat , ngInclude or other directive that creates new scope then you can check in controller function and verify that this ng-click="test(this)" will pass something as $scope :

$scope.test = function(something) {
    console.log(something === $scope); // => true
}

Another example. With ngRepeat you get new child scope per iteration, so in this case if you have this list:

<li ng-repeat="n in numbers">
    <button ng-click="test(this)">{{n}}</button>
</li>

you will have something being a child of the main $scope :

$scope.test = function(something) {
    console.log(something.$parent === $scope); // => true
};

Demo: http://plnkr.co/edit/nxxCn7SYUA4PfJpJoueu?p=info