Function parseTemplate

06.Router/basic/js/vue.js:3662–3695

* Process the template option and normalizes it into a * a DocumentFragment that can be used as a partial or a * instance template. * * @param {*} template * Possible values include: * - DocumentFragment object * - Node object of type Template * -

(template, shouldClone, raw)

   */

  function parseTemplate(template, shouldClone, raw) {
    var node, frag;

    // if the template is already a document fragment,
    // do nothing
    if (isFragment(template)) {
      trimNode(template);
      return shouldClone ? cloneNode(template) : template;
    }

    if (typeof template === 'string') {
      // id selector
      if (!raw && template.charAt(0) === '#') {
        // id selector can be cached too
        frag = idSelectorCache.get(template);
        if (!frag) {
          node = document.getElementById(template.slice(1));
          if (node) {
            frag = nodeToFragment(node);
            // save selector to cache
            idSelectorCache.put(template, frag);
          }
        }
      } else {
        // normal string template
        frag = stringToFragment(template, raw);
      }
    } else if (template.nodeType) {
      // a direct node
      frag = nodeToFragment(template);
    }

    return frag && shouldClone ? cloneNode(frag) : frag;
  }

var template = Object.freeze({
    cloneNode: cloneNode,