当与查询参数一起使用时，Ember .observe() 返回回调两次 [英] Ember .observe() returns callback twice when used with query-params

问题描述

http://jsbin.com/vowup/2

如果我点击更改为随机，程序会在控制台登录两次.

If I click change to random, program logs in console twice.

出于某种奇怪的原因，将修订版变量设置为字符串时它可以正常工作，但为数字或任何其他类型的变量记录两次

For some strange reason it works ok when setting revision variable to string, but logs twice for number or any other kind of variable

推荐答案

把你的代码改成这样，答案就清楚了:

Change your code to this and the answer will become clear:

  toggleHistory: (function() {
    console.log(this.get("revision"));
  }).observes("revision")

您将看到如下输出:

0.7038348997011781
"0.7038348997011781"

您的数字被强制转换为字符串.这是由这一行引起的:

Your numbers are being coerced to strings. That is caused by this line:

queryParams: ["revision"]

查询系统正在侦听更改并将每个新值转换为字符串，因此它可以作为 URL 的一部分出现.这就是为什么您会收到两个更改的事件.

Query system is listening to changes and converting every new value into string, so it could appear as part of the URL. That's why you get two changed events.

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