Translation with HTML

dom.js

// <dg-lang de="" en=""></dg-lang>
class TTSLANG extends HTMLElement {
    connectedCallback() {
        if (getUrlParam("lang") == "en") {
            this.innerHTML = this.getAttribute('en');
        } else if (getUrlParam("lang") == "de") {
            this.innerHTML = this.getAttribute('de');
        }
    }
}
customElements.define("dg-lang", TTSLANG);

/*
DE:
https://example.com/?lang=de --> <dg-lang de="Zugriff" en="Access">Zugriff</dg-lang>
EN:
https://example.com/?lang=en --> <dg-lang de="Zugriff" en="Access">Access</dg-lang>
*/

function getUrlParam(param) {
    param = param.replace(/([\[\](){}*?+^$.\\|])/g, "\\$1");
    var regex = new RegExp("[?]" + param + "=([^&#]*)");
    var url = decodeURIComponent(window.location.href);
    var match = regex.exec(url);
    return match ? match[1] : "";
}