ikea.js

function bookmarklet(countryList) {
  const priceElClass = "pip-price-module__current-price";
  function createPriceEl(href, cnt, el) {
    fetch(href).then(response => response.text()).then(data => {
      var doc = new DOMParser().parseFromString(data, "text/html");
      var price = doc.evaluate("//*[contains(@class, '"+priceElClass+"')]", doc, null, 4, null).iterateNext();
      var text = cnt.substr(0, 2) + ': ' + (price === null ? "-" : price.firstChild.textContent);
      var priceDiv = document.createElement("div");
      var priceA = document.createElement("a");
      priceA.setAttribute("href", href);
      priceA.appendChild(document.createTextNode(text));
      priceDiv.appendChild(priceA);
      el.appendChild(priceDiv);
    });
  }
  if (/ikea\.com$/.test(window.location.hostname)) {
    var url = window.location.pathname;
    var cur = url.slice(1, 6);
    var countries = countryList.split(",").filter(el => el != cur);
    if (/\/shoppingcart/.test(url)) {
      [...document.querySelectorAll("div[itemscope]")].map(function(el) {
        var urlProd = el.querySelector("a").href;
        var priceEl = el.querySelector("div[class^='price_total']"); 
        countries.forEach(function(cnt) {
          var href = urlProd.replace(cur, cnt);
          createPriceEl(href, cnt, priceEl.parentElement);
        }); 
      });
    } else if (/\/favourites/.test(url)) {
      [...document.querySelectorAll(".list-ingka-price-module")].map(function(el) {
        var urlProd = el.querySelector("a").href;
        var priceEl = el.querySelector(".list-ingka-price__sr-text"); 
        countries.forEach(function(cnt) {
          var href = urlProd.replace(cur, cnt);
          createPriceEl(href, cnt, priceEl.parentElement);
        });
      });
    } else {
      var urlProd = url.slice(6, );
      countries.forEach(function(cnt) {
        var href = "https://www.ikea.com/" + cnt + urlProd;
        createPriceEl(href, cnt, document.querySelector("."+priceElClass).parentElement.parentElement);
      })
    }
  }
};

var chosen = document.getElementsByClassName('selected');
var button = document.getElementById('bookmarklet');

function checkChosen() {
  if (chosen.length == 0) {
    button.style.backgroundColor = 'lightgray';
  } else {
    button.style.backgroundColor = '#0051ba';
  }
}
checkChosen();

function updateButton() {
  // modify actual js code for the bookmarklet
  if (chosen.length > 0) {
    var text = [...chosen].map((el) => el.firstChild.href.slice(-6, -1)).join(",");
    button.href = encodeURI("javascript:("+bookmarklet+")(\""+text+"\")");
  } else {
    button.href = "";
  }
}

function refreshScript() {
  checkChosen();
  var text = " (" + [...chosen].map((el) => el.firstChild.href.slice(-6, -4)).join(", ") + ")";
  button.innerText = "check price" + (chosen.length > 0 ? text : "");
  updateButton();
}

function toggleSelection(e) {
  e.classList.toggle('selected');
  refreshScript();
}

var items = document.getElementsByTagName('li');

[...items].forEach(elem => elem.addEventListener("click", function(el) {
  el.preventDefault(); 
  toggleSelection(this);
}));

var regions = document.getElementsByTagName('h3');

[...regions].forEach(elem => elem.addEventListener("click", function(el) {
  el.preventDefault();
  [...this.nextElementSibling.children].forEach(li => toggleSelection(li));
}));