[lit-helpers] appendTemplate

Usually you want to render a template to a container, and let lit-html handle subsequent updates.

Other times, you just want a quick-and-easy way to generate a chunk of DOM from some state, and then append it to some container, without caring about future updates.

for that, we could provide appendTemplate

function appendTemplate(template, target) {
  const tmp = document.createElement('div');
  render(template, tmp);
  const { firstElementChild } = tmp;
  target.appendChild(firstElementChild);
  tmp.remove();
  return firstElementChild;
}

A good reason not to do this is that it breaks one of lit-html’s main advantages, namely targetted updates. We could call it expensiveAppendTemplate or something?

[LarsDenBakker]

Lit html has a new template content directive. Sounds like that should be used here + a test fixture?

[LarsDenBakker]

To me render implies displaying something on the screen, not that it creates an element that isnt commected.