code: function (data, callback) {
              var html = '';
              var self = this;
              var fn = self.fn;
              callback = callback || function (error, ret) {
                  html = ret;
              };
              var name = self.config.name;
              if (!name && fn.TPL_NAME) {
                  name = fn.TPL_NAME;
              }
              var scope = new Scope(data), buffer = new LinkedBuffer(callback).head;
              renderTpl({
                  name: name,
                  fn: fn,
                  session: {},
                  root: self
              }, scope, buffer);
              return html;
          }
docs: get result by merge data with template
  @param data
  @param callback function called
  @return {String}