interceptor short-circuiting

service.clj

(ns terminator.service
  (:require [io.pedestal.http :as http]
            [io.pedestal.http.route :as route]
            [io.pedestal.http.body-params :as body-params]
            [io.pedestal.interceptor :as i]
            [ring.util.response :as ring-resp]))

(defn about-page
  [request]
  (ring-resp/response (format "Clojure %s - served from %s"
                              (clojure-version)
                              (route/url-for ::about-page))))

(defn home-page
  [request]
  (io.pedestal.log/info :msg "In Home Page!")
  (ring-resp/response "Hello World!"))

(def terminator
  (i/interceptor
   {:name  ::terminator
    :enter (fn [ctx]
             (io.pedestal.log/info :msg "In Terminator")
             (if (= "y" (get-in ctx [:request :params :t]))
               (assoc ctx :response (ring-resp/response "Terminated!"))
               ctx))
    :leave (fn [ctx]
             (io.pedestal.log/info :msg "Leaving Terminator")
             ctx)}))

(def terminator2
  (i/interceptor
   {:name  ::terminator2
    :enter (fn [ctx]
             (io.pedestal.log/info :msg "In Terminator2")
             (if (= "yy" (get-in ctx [:request :params :t]))
               (assoc ctx :response (ring-resp/response "Terminated 2!"))
               ctx))
    :leave (fn [ctx]
             (io.pedestal.log/info :msg "Leaving Terminator2")
             ctx)}))

;; Defines "/" and "/about" routes with their associated :get handlers.
;; The interceptors defined after the verb map (e.g., {:get home-page}
;; apply to / and its children (/about).
(def common-interceptors [(body-params/body-params) http/html-body])

;; Tabular routes
(def routes #{["/" :get (into common-interceptors [`terminator `terminator2 `home-page])]
              ["/about" :get (conj common-interceptors `about-page)]})

;; Map-based routes
;(def routes `{"/" {:interceptors [(body-params/body-params) http/html-body]
;                   :get home-page
;                   "/about" {:get about-page}}})

;; Terse/Vector-based routes
;(def routes
;  `[[["/" {:get home-page}
;      ^:interceptors [(body-params/body-params) http/html-body]
;      ["/about" {:get about-page}]]]])


;; Consumed by terminator.server/create-server
;; See http/default-interceptors for additional options you can configure
(def service {:env          :prod
              ;; You can bring your own non-default interceptors. Make
              ;; sure you include routing and set it up right for
              ;; dev-mode. If you do, many other keys for configuring
              ;; default interceptors will be ignored.
              ;; ::http/interceptors []
              ::http/routes routes

              ;; Uncomment next line to enable CORS support, add
              ;; string(s) specifying scheme, host and port for
              ;; allowed source(s):
              ;;
              ;; "http://localhost:8080"
              ;;
              ;;::http/allowed-origins ["scheme://host:port"]

              ;; Root for resource interceptor that is available by default.
              ::http/resource-path "/public"

              ;; Either :jetty, :immutant or :tomcat (see comments in project.clj)
              ::http/type              :jetty
              ;;::http/host "localhost"
              ::http/port              8080
              ;; Options to pass to the container (Jetty)
              ::http/container-options {:h2c? true
                                        :h2?  false
                                        ;:keystore "test/hp/keystore.jks"
                                        ;:key-password "password"
                                        ;:ssl-port 8443
                                        :ssl? false}})