Function stringToFragment

06.Router/basic/js/vue.js:3491–3532

* Convert a string template to a DocumentFragment. * Determines correct wrapping by tag types. Wrapping * strategy found in jQuery & component/domify. * * @param {String} templateString * @param {Boolean} raw * @return {DocumentFragment}

(templateString, raw)

   */

  function stringToFragment(templateString, raw) {
    // try a cache hit first
    var cacheKey = raw ? templateString : templateString.trim();
    var hit = templateCache.get(cacheKey);
    if (hit) {
      return hit;
    }

    var frag = document.createDocumentFragment();
    var tagMatch = templateString.match(tagRE$1);
    var entityMatch = entityRE.test(templateString);
    var commentMatch = commentRE.test(templateString);

    if (!tagMatch && !entityMatch && !commentMatch) {
      // text only, return a single text node.
      frag.appendChild(document.createTextNode(templateString));
    } else {
      var tag = tagMatch && tagMatch[1];
      var wrap = map[tag] || map.efault;
      var depth = wrap[0];
      var prefix = wrap[1];
      var suffix = wrap[2];
      var node = document.createElement('div');

      node.innerHTML = prefix + templateString + suffix;
      while (depth--) {
        node = node.lastChild;
      }

      var child;
      /* eslint-disable no-cond-assign */
      while (child = node.firstChild) {
        /* eslint-enable no-cond-assign */
        frag.appendChild(child);
      }
    }
    if (!raw) {
      trimNode(frag);
    }
    templateCache.put(cacheKey, frag);
    return frag;
  }

  /**
   * Convert a template node to a DocumentFragment.