version-menu.js.gotmpl

const versions = [
{{- range $version := .Versions }}
  {path: "{{ $version.Path }}", text: "{{ $version.Text }}", selected: {{ $version.Selected }} },
{{- end}}
];

// Material theme

function addMaterialMenu(elt, versions) {
  const current = versions.find(function (value) {
      return value.selected
  })

  const rootLi = document.createElement('li');
  rootLi.classList.add('md-nav__item');
  rootLi.classList.add('md-nav__item--nested');

  const input = document.createElement('input');
  input.classList.add('md-toggle');
  input.classList.add('md-nav__toggle');
  input.setAttribute('data-md-toggle', 'nav-10000000');
  input.id = "nav-10000000";
  input.type = 'checkbox';

  rootLi.appendChild(input);

  const lbl01 = document.createElement('label')
  lbl01.classList.add('md-nav__link');
  lbl01.setAttribute('for', 'nav-10000000');
  lbl01.textContent = current.text + " ";

  rootLi.appendChild(lbl01);

  const nav = document.createElement('nav')
  nav.classList.add('md-nav');
  nav.setAttribute('data-md-component','collapsible');
  nav.setAttribute('data-md-level','1');

  rootLi.appendChild(nav);

  const lbl02 = document.createElement('label')
  lbl02.classList.add('md-nav__title');
  lbl02.setAttribute('for', 'nav-10000000');
  lbl02.textContent = current.text + " ";

  nav.appendChild(lbl02);

  const ul = document.createElement('ul')
  ul.classList.add('md-nav__list');
  ul.setAttribute('data-md-scrollfix','');

  nav.appendChild(ul);

  for (let i = 0; i < versions.length; i++) {
    const li = document.createElement('li');
    li.classList.add('md-nav__item');

    ul.appendChild(li);

    const a = document.createElement('a');
    a.classList.add('md-nav__link');
    if (versions[i].selected) {
      a.classList.add('md-nav__link--active');
    }
    a.href = window.location.protocol + "//" + window.location.host + "/" + window.location.pathname.split("/")[1] + "/";
    if (versions[i].path) {
      a.href = a.href + "/" + versions[i].path + "/"
    }
    a.title = versions[i].text;
    a.text = versions[i].text;

    li.appendChild(a);
  }

  elt.appendChild(rootLi);
}

const materialSelector = 'div.md-container main.md-main div.md-main__inner.md-grid div.md-sidebar.md-sidebar--primary div.md-sidebar__scrollwrap div.md-sidebar__inner nav.md-nav.md-nav--primary ul.md-nav__list';

addMaterialMenu(elt, versions);