Backbone.js不会发出跨主机请求？

Question

我一直在Chrome控制台中使用Backbone,遇到了一个我无法弄清楚的跨域问题.

我正在连接的主机可能正确地实现了CORS,因为原始XHR请求返回了预期的JSON:

var http = new XMLHttpRequest();
http.open('GET', 'http://example.com:3000/entities/item/15.json', true);
http.onreadystatechange = function(evt) { console.log(evt); }
http.send();

(在控制台上记录3个XHR进度事件,并在响应中记录正确的数据)

但是当我使用Backbone执行以下操作时,浏览器不喜欢它:

var Item = Backbone.Model.extend({});
var ItemsCollection = Backbone.Collection.extend({
  model: Item,
  url: 'http://example.com:3000/entities/item/'
});
var items = new ItemsCollection();
items.fetch();

(退货XMLHttpRequest cannot load http://example.com:3000/entities/item/. Origin http://localhost:8000 is not allowed by Access-Control-Allow-Origin.)

有什么我需要做的告诉Backbone与CORS一起工作吗？这个错误似乎是在浏览器发出请求之前出现的,所以我认为这不是服务器配置错误.

Answer 1

我希望其中一个有帮助(我还没试过):
1.重写Backbone.js同步以允许Cross Origin

(function() {
  var proxiedSync = Backbone.sync;
  Backbone.sync = function(method, model, options) {
    options || (options = {});
    if (!options.crossDomain) {
      options.crossDomain = true;
    }
    if (!options.xhrFields) {
      options.xhrFields = {withCredentials:true};
    }
    return proxiedSync(method, model, options);
  };
})();

2. 对backbone.js的跨域CORS支持

$.ajaxPrefilter(function(options, originalOptions, jqXHR) {
    options.crossDomain ={
        crossDomain: true
    };
    options.xhrFields = {
        withCredentials: true
    };
});

Answer 2

嘿,你可以使用类似的东西:

 var PostsCollection = Backbone.Collection.extend({
   initialize: function(models, options) {
     //this.id = options.id;
   },
   url: 'http://myapi/api/get_posts/?count=8',
 });

 posts = new PostsCollection();
 posts.fetch({
   dataType: 'jsonp',
   success : function (data) {
     console.log(data);
   }
 });

关键是我们需要使用'jsonp'