code: function (filePath, model, cb) {
              var callback = function (err, html) {
                  if (err) {
                      return cb(err);
                  }
                  return cb(null, html);
              };
              if (cache[filePath] && isProd) {
                  cache[filePath](model, callback)
              } else {
                  saker.getView(filePath, function (err, template) {
                      if (err) {
                          return cb(err);
                      }
                      try {
                          var compiled = saker.compile(template, filePath);
                      } catch (err) {
                          return cb(err);
                      }
                      if (isProd) {
                          cache[filePath] = compiled;
                      }
                      compiled(model, callback);
                  })
              }
          }
docs: 根据文件路径和数据生成html。Generate html according to file path and data model.
  @param filePath
  @param model
  @param cb