javascript - Backbone : Wait for multiple fetch to continue

Question

我获取多个页面的集合，我正在寻找一种方法来了解何时完成所有获取。这是我的收藏的样子:

app.collections.Repos = Backbone.Collection.extend({
  model: app.models.Repo,
  initialize: function(last_page){
    this.url = ('https://api.github.com/users/' + app.current_user + '/watched');

    for (var i = 1; i <= last_page; i++) {
      this.fetch({add: true, data: {page: i}});  
    };
  }, ...

知道如何使用干净的代码实现这一点吗？

Answer 1

使用 jQuery deferreds :

var deferreds = [];
for (var i = 1; i <= last_page; i++) {
  deferreds.push(this.fetch({add: true, data: {page: i}}));
};

$.when.apply($, deferreds).done(function() {
  ...
  <CODE HERE>
  ...
}

(我还没有实际测试过这个，但我认为它应该有效。)

关于 when 的 jQuery 文档:

Provides a way to execute callback functions based on one or more objects, usually Deferred objects that represent asynchronous events.

另一个可能有帮助的答案:How do you work with an array of jQuery Deferreds?