export default class extends HTMLElement { connectedCallback () { this.button.addEventListener('click', () => { const expirationDate = new Date() expirationDate.setFullYear(expirationDate.getFullYear() + 10) const expires = expirationDate.toUTCString() document.cookie = this.dataset.key + '=' + this.dataset.value + '; expires=' + expires + '; path=/' }) } get button () { return this.querySelector('button') } }