setting cross-subdomain cookie with javascript

Question

How should I add domain support to these functions? I want to achieve that .example.com is declared as domain, so that the cookies can be read across all subdomains of the e

Answer 1

In my case we needed to set a cookie that would work across our .com subdomains:

function setCrossSubdomainCookie(name, value, days) {
  const assign = name + "=" + escape(value) + ";";
  const d = new Date();
  d.setTime(d.getTime() + (days*24*60*60*1000));
  const expires = "expires="+ d.toUTCString() + ";";
  const path = "path=/;";
  const domain = "domain=" + (document.domain.match(/[^\.]*\.[^.]*$/)[0]) + ";";
  document.cookie = assign + expires + path + domain;
}

This might not work for .co.uk etc but the principle can be used