jeasyui combotree中，Ajax异步加载时，使用缓存，可以让其他字段共用该数据

ajax-combotree-using-cache

/**
 * jeasyui combotree中，Ajax异步加载时，使用缓存，可以让其他字段共用该数据
 * todo: 没有成功
 */
$('#city_id').combotree({
  textField: 'name',
  valueField: 'id',
  multiple: false,
  onBeforeLoad: function(param){
    console.log('onBeforeLoad');
    var selected = $('#city_id').combotree('tree').tree('getChecked');
    console.log(selected);
    if(selected){
      var children = selected.hasOwnProperty('children') ? $('#city_id').combotree('tree').tree('getChildren', selected.target) : false;
    }
    console.log(children);
    if(children && children.length > 0){
      console.log('false');
      return false;
    }
    $.post(ROOT + 'Home/Area/getComboTree', {
      id: param ? param : 0
    }, function(data){
      var data = eval("(" + data + ")");
      if(data){
        if(!selected){
          $('#city_id').combotree('tree').tree('loadData', data);
        }else{
          $('#city_id').combotree('tree').tree('append', {
            parent: selected.target,
            data: data
          });
        }
      }
    });
    return false;
  },
  onLoadSuccess: function(){
  }
}).next().find('.validatebox-text').attr('placeholder', '请选择出发城市');