fb_element_grabber.js

// ==UserScript==
// @name         Facebook Elements Grabber
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://*.facebook.com/abestexpressph/inbox*
// @grant        none
// ==/UserScript==

(function(window) {

    let fb = {
      name: document.getElementsByClassName('ellipsis'),

      copyToClipboard: function(string) {
        var el = document.createElement('textarea');
        el.value = string;
        el.setAttribute('readonly', '');
        el.style = {position: 'absolute', left: '-9999px'};
        document.body.appendChild(el);
        el.select();
        document.execCommand('copy');
        document.body.removeChild(el);
      },

      focusTextarea: function() {
        let textbox = document.getElementsByClassName('uiTextareaAutogrow')[0];
        textbox.style.border = 'solid 5px solid #ff0000 !important';
        textbox.focus();
        setTimeout ( textbox.style.border = '', 500);
      },

      focusThread: function() {
        document.getElementsByClassName('uiScrollableAreaContent')[0].focus();
      },

      getName: function(error) {
         let sender_name = this.name[1].textContent;
         if (sender_name != '') {
           this.copyToClipboard(sender_name);
         }
      },

      foobar: function() {
          alert('foobar');
      },

      testigo: function() {
          alert('testigo');
      }
    };


    window.fb = fb;

})(window);