tampermonkey script stops working if I change the page

Question

I am using Tampermonkey to save time on frequent tasks. The goal is to get content of an element on www.example1.com, navigate to another page, and do stuff there. The start

Answer 1

Allow the userscript on both urls and use GM_setValue/GM_getValue to organize the communication.

//@match   http://example1.com
//@match   http://example2.com
//@grant   GM_getValue
//@grant   GM_setValue

if (location.href.indexOf('http://example1.com') == 0) {
    GM_setValue('id', Date.now() + '\n' + document.getElementById("myId").textContent);
    window.open("http://example2.com","_self");
} else if (location.href.indexOf('http://example2.com') == 0) {
    var ID = GM_getValue('id', '');
    if (ID && Date.now() - ID.split('\n')[0] < 10*1000) {
        ID = ID.split('\n')[1];
        .............. use the ID
    }
}

• This is a simplified example. In the real code you may want to use location.host or location.origin or match location.href with regexp depending on what the real urls are.

• To pass complex objects serialize them:

  GM_setValue('test', JSON.stringify({a:1, b:2, c:"test"}));
  

  try { var obj = JSON.parse(GM_getValue('test')); }
  catch(e) { console.error(e) }