template('*', {
    title: 'Lorem ipsum dolor sit amet.',
    body: 'Lorem ipsum dolor sit amet, consectetur adipisicing elit. Eos, optio.'
  });

  function template(selector, data) {
    [].forEach.call(document.querySelectorAll(selector), function(node) {
      node.innerHTML = tag(node.innerHTML, data);
    });
  }

  function tag(input, data) {
    for (var key in data) {
      input = input.replace(new RegExp('{{'+ key +'}}', 'g'), data[key]);
    }
    return input;
  }