为什么 window.open() 在循环中通过 setTimeout() 调用时会被静默忽略? [英] Why is window.open() silently ignored iff called from within a loop and via setTimeout()?

问题描述

--- 编辑.

我不明白；昨天它似乎被忽略了；现在它似乎正在工作.即使在循环中并通过 setTimeout() 调用.目前，我似乎很难复制昨天的行为......这是怎么回事?

I don't get it; yesterday it seemed to be ignored; now it seems to be working. Even within loop and called via setTimeout(). Currently I seem to be having difficulties replicating yesterday's behaviour... What is going on?

--- 第二次编辑.

第一个想法是如何修复"问题的复制:奇怪的是，这是否有效似乎取决于当前的 URL！例如.作品来自SE 站点，但不是来自 http://www.asdf.com/.怎么样?

First idea how to "fix" the replication of the issue: weirdly, whether or not this works seems to be dependent on the current URL! E.g. works from SE-sites, but not from, say, http://www.asdf.com/. How so?

而 setTimeout() 在这里工作:

Whereas setTimeout() works here:

setTimeout(function(){ alert("Hello"); }, 3000);

和 window.open() 在这里工作:

and window.open() works here:

window.open("https://www.bbc.com","_self");

甚至两者的结合在这里工作:

and even the combination of the two works here:

setTimeout(function(){ window.open("https://www.bbc.com","_self") }, 3000);

出乎意料地，两者的结合在一个循环中被 - 默默地 - 忽略了:

suddently and unexpectedly the combination of the two is - silently - ignored in a loop:

i=0;
while(i < 100)
{
    setTimeout(function(){ window.open("https://www.bbc.com","_self") }, 3000);
    i++
}

为什么?

tldr;

这个问题似乎已经出现了近一百万次，但还没有(据我所知/搜索)采用简洁的问答格式；例如

This question seems to have come up close to a million times already but not yet (as far as I could tell / search) with a succinct Q&A format; e.g.

Settimeout() javascript 函数被忽略

从第一原理"模拟 JavaScript 的 setTimeout() 方法

推荐答案

弹出大多数流行浏览器中的阻止程序仅允许打开一个新窗口，如果它是由于直接用户操作(例如单击)运行的代码而打开的.因为 setTimeout() 发生在未来某个时间，不被认为是用户操作的直接结果，所以尝试从 setTimeout() 打开窗口可能会被弹出窗口拦截器.

Popup blockers in most popular browsers will only allow a new window to be opened if it is opened as a result of code running from a direct user action such as a click. Because a setTimeout() happens some time in the future, is not considered the direct result of a user action so attempts to open windows from setTimeout() are likely blocked by the popup blocker.

本质上，尝试从 window.open 从内部 setTimeout() 触发 浏览器 为认为这是一个值得(静默)阻止的弹出窗口.-- 相反，如果 window.open 是自己触发的，浏览器会将其视为就像用户点击"，即不作为垃圾邮件被拦截.

In essence, trying to fire window.open from within setTimeout() leaves the browser to "think" it's a popup which deserves (silent) blocking. -- If, in contrast, window.open is fired on it's own, the browser treats seems to treat it like a "user click", that is, not as spam to be blocked.

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