javascript - 检测以 HTML 表单目标 ="_blank"和不同域打开的窗口的关闭

Question

出于某些原因，我需要使用原生 HTML 表单属性 target="_blank" 来在新窗口中显示表单响应。

我的 myDomain.com 中有以下 HTML 表单:

<form target="_blank" method="POST" action="http://www.anotherDomain.com/somePage">
  <input name="someFieldName" value="someValue"/>
  <button type="submit">Submit</button>
</form>

当用户单击提交时，浏览器中会出现一个窗口/选项卡，我无法控制来自anotherDomain.com 的表单响应。

如何检测_blank 窗口何时关闭？

如果使用 window.open()，我可以获得 child 的 window 引用，但它不合适，因为 window.open()会被浏览器拦截。

Answer 1

这是我的解决方案:

<!-- set form target to a specific name -->
<form target="windowName" method="POST" action="http://www.anotherDomain.com/somePage">
  <input name="someFieldName" value="someValue"/>
  <button type="submit">Submit</button>
</form>

<script>
var childWindow;

$('form').get(0).onsubmit = function () {
  // I think why window.open() here would not be blocked by browser because the function is attached to the HTML DOM and the event is triggered by user (mouse click)
  childWindow = window.open('', 'windowName');
};

var checkWindowClose = setInterval(function () {
  if (childWindow.closed) {
    alert('Window is closed');
    clearInterval(checkWindowClose);
  } else {
    // check the URL if childWindow has been redirected to somewhere
    try {
      // cross-origin exception will occur if the URL is in different domain
      if (childWindow.document.URL == 'something') {
        // ...
        clearInterval(checkWindowClose);
      }
    } catch (err) {
      // just ignore the error and do nothing
    }
  }
}, 1000);
</script>