如何从promise方法中访问角度js控制器的"this"？

Question

我有简单的角度js控制器,如下所示发出XHR请求

app.controller('MainController', ['$http', function($http) {

    this.php_response = {};

    var promise = $http.get('process.php');

    promise.then(
        function(success_data) {

            // I dont think "this" is talking to the controller this anymore?    
            this.php_response = success_data;

        }, function(error) {
            console.log('there was a problem');
        }
    );

}]);

当我使用$scope代码而不是代码编写此控制器时,现在该this.php_response属性不包含从XHR请求中检索的数据.
我怀疑promise.then#success回调不再引用控制器this.
如何在promise方法中访问它？

Answer 1

使用保留词汇上下文的箭头函数:

promise.then(success_data => {  
    this.php_response = success_data;
}, error => {
    console.log('there was a problem');
});

另一种简单的方法是使用Function.prototype.bind方法绑定上下文:

promise.then(function(success_data) {  
    this.php_response = success_data;
}.bind(this), function(error) {
    console.log('there was a problem');
});

最后,老派方式:定义指向外部的引用变量this并在回调中使用它:

var self = this;

promise.then(function(success_data) {  
    self.php_response = success_data;
}, function (error) {
    console.log('there was a problem');
});

无论你喜欢什么.