class HtmlEmail extends HTMLElement { constructor() { super(); this.attachShadow({ mode: 'open' }); let emailContent; try { emailContent = window.atob(this.dataset.content); } catch (error) { console.log(error); return; } const container = document.createElement('div'); container.innerHTML = emailContent; this.shadowRoot.appendChild(container); } } customElements.define('html-email', HtmlEmail);