BrnLng / OptionsGrabber

// ==UserScript==
// @name         OptionsGrabber
// @namespace    http://tampermonkey.net/
// @version      0.1201903281649
// @license      MIT
// @description  grab options from a html form select
// @author       BrnLng
// @grant        none
// @include      *
// ==/UserScript==

// @match        https://www.w3schools.com/html/tryit.asp?filename=tryhtml_elem_select
// @match        *://www.debentures.com.br/*

function displayResult() {
  var list = document.getElementsByTagName('select');
  var txt = "";

  for (var i = 0; i < list.length; i++) {
    txt = txt + list[i].name + ":\n";
    for (var j = 0; j < list[i].options.length; j++) {
      txt = txt + "  " + list[i].options[j].label + " [" + list[i].options[j].value + "]\n";
    }
  }
  alert(txt);
}

(function() {
    'use strict';

    var test = document.getElementsByTagName('select');
    if (test.length > 0) {
        var css = ".BrnButtonGrabber { font-size: 0.7em; background: #fca838; border: 0; padding: .7em; margin-left: .7em; position: relative; top: -.25em; border-radius: 1.4em; }";
        var style = document.createElement("style");
        style.type = "text/css";
        style.appendChild(document.createTextNode(css));
        document.head.appendChild(style);

        var btn = document.createElement("button");
        btn.innerHTML = "Grab options!";
        btn.classList.add("BrnButtonGrabber");
        btn.onclick = () => {
            displayResult();
            return false;
        };
        document.getElementsByTagName('select')[0].after(btn);
    }

})();