browser/libs/dom.js
function _getElement(name, parentNode) {
    if (name === '') name = null;
    var _elem;
    var _isarr = false;
    if (typeof name === 'string') {
      if (name[0] == '<') {
        _elem = window.document.createElement('div');
        _elem.innerHTML = name;
        if (_elem.childNodes.length == 1) {
          _elem = _elem.childNodes[0];
          _isarr = false;
        }
        else {
          _elem = _elem.childNodes;
          _isarr = true;
        }
      }
      else {
        if (name.indexOf('<') > 0 || name.indexOf('>') > 0)
          throw new Error('Syntax error, unrecognized');

        var names = name.split(' ');
        var nodes = parentNode ? [parentNode] : null;
        for (var i = 0; i < names.length; i++) {
          if (names[i] != '')
            nodes = _matchElement(nodes, names[i], !!parentNode);
        }
        if (nodes.length <= 1) {
          _elem = nodes[0];
          _isarr = false;
        } else {
          _elem = nodes;
          _isarr = true;
        }
      }
    } else {
      _elem = name;
    }
    return {_elem, _isarr};
  }
function _getElement(name, parentNode) {
    if (name === '') name = null;
    var _elem;
    var _isarr = false;
    if (typeof name === 'string') {
      if (name[0] == '<') {
        _elem = window.document.createElement('div');
        _elem.innerHTML = name;
        if (_elem.childNodes.length == 1) {
          _elem = _elem.childNodes[0];
          _isarr = false;
        }
        else {
          _elem = _elem.childNodes;
          _isarr = true;
        }
      }
      else {
        if (name.indexOf('<') > 0 || name.indexOf('>') > 0)
          throw new Error('Syntax error, unrecognized');

        var names = name.split(' ');
        var nodes = parentNode ? [parentNode] : null;
        for (var i = 0; i < names.length; i++) {
          if (names[i] != '')
            nodes = _matchElement(nodes, names[i], !!parentNode);
        }
        if (nodes.length <= 1) {
          _elem = nodes[0];
          _isarr = false;
        } else {
          _elem = nodes;
          _isarr = true;
        }
      }
    } else {
      _elem = name;
    }
    return {_elem, _isarr};
  }
- parentNode 仅筛选此节点下的节点.