如何创建一个 Restas 全局装饰器答案

【问题标题】：How to create a Restas global decorator如何创建一个 Restas 全局装饰器
【发布时间】：2015-04-22 04:25:58
【问题描述】：

如何在 RESTAS 中创建全局装饰器？

;;;; defmodule.lisp
(in-package #:restas)
(defclass fake-server-route (routes:proxy-route) ())
(defun @fake-server (route)
  (make-instance 'fake-server-route :target route))
(defmethod restas:process-route :before ((route fake-server-route) bindings)
  (setf (hunchentoot:header-out :server) "Powered by NodeJS"))

(restas:define-module #:myapp
  (:use #:cl #:st-json)
  (:render-method #'st-json:write-json-to-string)
  (:content-type "application/json")
  (:decorators #'restas:@fake-server) ; this line here does not work
  ; it gives The symbol "@FAKE-SERVER" is not external in the RESTAS package.
  )

(in-package #:myapp)

(defparameter *template-directory*
  (merge-pathnames #P"templates/" myapp-config:*base-directory*))

(defparameter *static-directory*
  (merge-pathnames #P"static/" myapp-config:*base-directory*))

如果我将@fake-server 设置为其他包中的外部符号并尝试使用它，它仍然无法工作，它会给出类似：

defpackage 错误，未知选项：decorators

使用双冒号表示：

    COMPILE-FILE-ERROR while
compiling #<CL-SOURCE-FILE "myapp" "defmodule">
   [Condition of type UIOP/LISP-BUILD:COMPILE-FILE-ERROR]

Backtrace:
  0: (UIOP/LISP-BUILD:CHECK-LISP-COMPILE-RESULTS NIL T T "~/asdf-action::format-action/" ((#<ASDF/LISP-ACTION:COMPILE-OP > . #<ASDF/LISP-ACTION:CL-SOURCE-FILE "myapp" "defmodule">)))
  1: ((SB-PCL::EMF ASDF/ACTION:PERFORM) #<unused argument> #<unused argument> #<ASDF/LISP-ACTION:COMPILE-OP > #<ASDF/LISP-ACTION:CL-SOURCE-FILE "myapp" "defmodule">)
  2: ((:METHOD ASDF/ACTION:PERFORM-WITH-RESTARTS :AROUND (T T)) #<ASDF/LISP-ACTION:COMPILE-OP > #<ASDF/LISP-ACTION:CL-SOURCE-FILE "myapp" "defmodule">) [fast-method]
  3: ((:METHOD ASDF/PLAN:PERFORM-PLAN (LIST)) ((#1=#<ASDF/LISP-ACTION:COMPILE-OP > . #<ASDF/SYSTEM:SYSTEM "alexandria">) (#1# . #<ASDF/COMPONENT:MODULE #2="trivial-features" "src">) (#1# . #<ASDF/SYSTEM:SY..
  4: ((FLET SB-C::WITH-IT :IN SB-C::%WITH-COMPILATION-UNIT))
  5: ((:METHOD ASDF/PLAN:PERFORM-PLAN :AROUND (T)) ((#1=#<ASDF/LISP-ACTION:COMPILE-OP > . #<ASDF/SYSTEM:SYSTEM "alexandria">) (#1# . #<ASDF/COMPONENT:MODULE #2="trivial-features" "src">) (#1# . #<ASDF/SYST..
  6: ((FLET SB-C::WITH-IT :IN SB-C::%WITH-COMPILATION-UNIT))
  7: ((:METHOD ASDF/PLAN:PERFORM-PLAN :AROUND (T)) #<ASDF/PLAN:SEQUENTIAL-PLAN {1009701223}> :VERBOSE NIL) [fast-method]
  8: ((:METHOD ASDF/OPERATE:OPERATE (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)) #<ASDF/LISP-ACTION:LOAD-OP :VERBOSE NIL> #<ASDF/SYSTEM:SYSTEM "myapp"> :VERBOSE NIL) [fast-method]
  9: ((SB-PCL::EMF ASDF/OPERATE:OPERATE) #<unused argument> #<unused argument> #<ASDF/LISP-ACTION:LOAD-OP :VERBOSE NIL> #<ASDF/SYSTEM:SYSTEM "myapp"> :VERBOSE NIL)
 10: ((LAMBDA NIL :IN ASDF/OPERATE:OPERATE))
 11: ((:METHOD ASDF/OPERATE:OPERATE :AROUND (T T)) #<ASDF/LISP-ACTION:LOAD-OP :VERBOSE NIL> #<ASDF/SYSTEM:SYSTEM "myapp"> :VERBOSE NIL) [fast-method]
 12: ((SB-PCL::EMF ASDF/OPERATE:OPERATE) #<unused argument> #<unused argument> ASDF/LISP-ACTION:LOAD-OP "myapp" :VERBOSE NIL)
 13: ((LAMBDA NIL :IN ASDF/OPERATE:OPERATE))
 14: (ASDF/CACHE:CALL-WITH-ASDF-CACHE #<CLOSURE (LAMBDA NIL :IN ASDF/OPERATE:OPERATE) {10096ADFDB}> :OVERRIDE NIL :KEY NIL)
 15: ((:METHOD ASDF/OPERATE:OPERATE :AROUND (T T)) ASDF/LISP-ACTION:LOAD-OP "myapp" :VERBOSE NIL) [fast-method]
 16: ((:METHOD ASDF/OPERATE:OPERATE :AROUND (T T)) ASDF/LISP-ACTION:LOAD-OP "myapp" :VERBOSE NIL) [fast-method]
 17: ((LAMBDA NIL :IN QUICKLISP-CLIENT::APPLY-LOAD-STRATEGY))

【问题讨论】：

标签： web lisp common-lisp decorator hunchentoot

【解决方案1】：

The symbol "@FAKE-SERVER" is not external in the RESTAS package

您仍然可以使用双冒号表示法访问此符号，即#'restas::@fake-server。

但是，由于您不是 restas 包的作者，您可能希望在自己的包中定义 @fake-server-函数。

我无法帮助您解决后续问题，因为据我了解文档，您正确使用了装饰器选项。

【讨论】：