角2的承诺？ [英] Angular 2 Promises?

问题描述

我使用角fullstack创建一个应用程序。在我的应用程序，我使用Yelp API来获取搜索结果，我想在一个变量来存储（注：this.searchTerm在HTML通过NG-模式改变）：

I am using angular-fullstack to create an app. In my app, I use the Yelp API to get search results, which I want to store in a variable (Note: this.searchTerm is changed via an ng-model in the HTML):

'use strict';

(function() {

class MainController {

  constructor($http) {
    this.$http = $http;
    this.awesomeThings = [];
    this.searchTerm = "";
    this.data = [];
  }

  addThing() {
    this.$http.get('/api/messages/city/' + this.searchTerm).success(function(res){
      this.data = res;
    });
  };
}

angular.module('nightlifeApp').controller('MainController', MainController);})();

当我这样做，我得到this.data没有定义的错误。我明白，这是做异步调用的本质，但我怎么能解决这个问题？

When I do so, I get an error that this.data is not defined. I understand that this is do to the nature of async calls, but how can I fix this?

感谢

推荐答案

的这个关键字里面不确定的一个。然后严格模式功能。设置一个局部变量来引用这个的然后函数内部具有约束力。

The this keyword is undefined inside a .then function in strict mode. Set a local variable to reference the this binding inside the then function.

'use strict';

(function() {

class MainController {

  constructor($http) {
    this.$http = $http;
    this.awesomeThings = [];
    this.searchTerm = "";
    this.data = [];
  }

  addThing() {
    var self = this;
    this.$http.get('/api/messages/city/' + this.searchTerm).then (function(res){
      self.data = res.data;
    });
  };
}

angular.module('nightlifeApp').controller('MainController', MainController);})();

另外， .success 方法的德precated 。使用。然后代替。

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