adl-support/src/adl_support/rest_support.clj
2018-07-29 00:37:57 +01:00

81 lines
2.7 KiB
Clojure

(ns adl-support.rest-support
(:require [adl-support.core :refer [do-or-log-error do-or-return-reason]]
[clojure.core.memoize :as memo]
[clojure.data.json :as json]
[clojure.java.io :as io]
[clojure.string :refer [split]]))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;
;;;; adl-support.rest-support: functions used by ADL-generated code: support
;;;; functions for REST routes.
;;;;
;;;; This program is free software; you can redistribute it and/or
;;;; modify it under the terms of the MIT-style licence provided; see LICENSE.
;;;;
;;;; This program is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;;; License for more details.
;;;;
;;;; Copyright (C) 2018 Simon Brooke
;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defmacro if-valid-user
"Evaluate this `form` only if there is a valid user in the session of
this `request`; otherwise return the `error-return` value."
;; TODO: candidate for moving to adl-support.core
([form request error-return]
`(log/debug "if-valid-user: " (-> ~request :session :user))
`(if
(-> ~request :session :user)
~form
~error-return))
([form request]
(if-valid-user form request nil)))
(defmacro valid-user-or-forbid
"Evaluate this `form` only if there is a valid user in the session of
this `request`; otherwise return an HTTP forbidden response."
;; TODO: candidate for moving to adl-support.core
[form request]
`(if-valid-user
~form
~request
{:status 403
:body (json/write-str "You must be logged in to do that")}))
(defmacro with-params-or-error
"Evaluate this `form` only if these `params` contain all these `required` keys;
otherwise return an HTTP 400 response."
;; TODO: candidate for moving to adl-support.core
[form params required]
`(if-not
(some #(not (% ~params)) ~required)
~form
{:status 400
:body (json/write-str (str "The following params are required: " ~required))}))
;; (with-params-or-error (/ 1 0) {:a 1 :b 2} #{:a :b :c})
;; (with-params-or-error "hello" {:a 1 :b 2} #{:a :b })
(defmacro do-or-server-fail
"Evaluate this `form`; if it succeeds, return an HTTP response with this
status code and the JSON-formatted result as body; if it fails, return an
HTTP 500 response."
[form status]
`(let [r# (do-or-return-reason ~form)]
(if
(some #(= :result %) (keys r#)) ;; :result might legitimately be bound to nil
{:status ~status
:body (:result r#)}
{:status 500
:body r#})))