example of just coercion with ring

examples/just-coercion-with-ring/.gitignore

@@ -0,0 +1,11 @@
+/target
+/classes
+/checkouts
+pom.xml
+pom.xml.asc
+*.jar
+*.class
+/.lein-*
+/.nrepl-port
+.hgignore
+.hg/

examples/just-coercion-with-ring/README.md

@@ -0,0 +1,39 @@
+# Just Coercion With Ring
+
+A Sample project showing how to use the reitit coercion with pure ring.
+
+* `Middleware` are turned into normal ring middleware via `reitit.middleware/chain`
+* Endpoint parameters are given to middleware as arguments
+* Coerced parameters are available from `:parameters`
+
+## Usage
+
+```clj
+> lein repl
+
+(require '[example.server :as server])
+
+;; the manually coerced version
+(require '[example.naive :as naive])
+(server/restart naive/app)
+
+;; schema-coercion
+(require '[example.schema :as schema])
+(server/restart schema/app)
+
+;; spec-coercion
+(require '[example.spec :as spec])
+(server/restart spec/app)
+
+;; data-spec-coercion
+(require '[example.dspec :as dspec])
+(server/restart dspec/app)
+```
+
+To test the endpoint:
+
+http://localhost:3000/?x=1&y=20
+
+## License
+
+Copyright © 2017 Metosin Oy

examples/just-coercion-with-ring/project.clj

@@ -0,0 +1,6 @@
+(defproject just-coercion-with-ring "0.1.0-SNAPSHOT"
+  :description "Reitit coercion with vanilla ring"
+  :dependencies [[org.clojure/clojure "1.9.0-RC2"]
+                 [ring "1.6.3"]
+                 [metosin/muuntaja "0.4.1"]
+                 [metosin/reitit "0.1.0-SNAPSHOT"]])

examples/just-coercion-with-ring/src/example/dspec.clj

@@ -0,0 +1,15 @@
+(ns example.dspec
+  (:require [reitit.ring.coercion :as coercion]
+            [reitit.ring.coercion.spec :as spec-coercion]
+            [example.server :as server]))
+
+(defn handler [{{{:keys [x y]} :query} :parameters}]
+  {:status 200
+   :body {:result (+ x y)
+          :source :data-spec}})
+
+(def app
+  (-> #'handler
+      (server/wrap-coercion
+        {:parameters {:query {:x int?, :y int?}}
+         :coercion spec-coercion/coercion})))

examples/just-coercion-with-ring/src/example/naive.clj

@@ -0,0 +1,27 @@
+(ns example.naive
+  (:require [clojure.spec.alpha :as s]
+            [clojure.walk :as walk]
+            [example.server :as server]))
+
+(s/def ::x int?)
+(s/def ::y int?)
+(s/def ::request (s/keys :req-un [::x ::y]))
+
+(defn ->long [x]
+  (try
+    (Long/parseLong x)
+    (catch Exception _
+      x)))
+
+(defn app [request]
+  (println (:query-params request))
+  (let [{:keys [x y] :as params} (-> (:query-params request)
+                                     (walk/keywordize-keys)
+                                     (update :x ->long)
+                                     (update :y ->long))]
+    (if (s/valid? ::request params)
+      {:status 200
+       :body {:result (+ x y)
+              :source :naive}}
+      {:status 400
+       :body "invalid input"})))

examples/just-coercion-with-ring/src/example/schema.clj

@@ -0,0 +1,15 @@
+(ns example.schema
+  (:require [reitit.ring.coercion :as coercion]
+            [reitit.ring.coercion.schema :as schema-coercion]
+            [example.server :as server]))
+
+(defn handler [{{{:keys [x y]} :query} :parameters}]
+  {:status 200
+   :body {:result (+ x y)
+          :source :schema}})
+
+(def app
+  (-> #'handler
+      (server/wrap-coercion
+        {:parameters {:query {:x Long, :y Long}}
+         :coercion schema-coercion/coercion})))

examples/just-coercion-with-ring/src/example/server.clj

@@ -0,0 +1,28 @@
+(ns example.server
+  (:require [ring.adapter.jetty :as jetty]
+            [reitit.ring.middleware :as middleware]
+            [reitit.ring.coercion :as coercion]))
+
+(defonce ^:private server (atom nil))
+
+;; unlift Middleware Record into vanilla Ring middleware
+;; NOTE: to support format-based body coercion, an options map needs
+;; to be set with :extract-request-format and extract-response-format
+(defn wrap-coercion [handler resource]
+  (middleware/chain
+    [coercion/coerce-request-middleware
+     coercion/coerce-response-middleware
+     coercion/coerce-exceptions-middleware]
+    handler
+    resource))
+
+(defn restart [handler]
+  (let [app (-> handler
+                (ring.middleware.params/wrap-params)
+                (muuntaja.middleware/wrap-format))]
+    (swap! server (fn [x]
+                    (when x (.stop x))
+                    (jetty/run-jetty
+                      handler
+                      {:port 3000, :join? false})))
+    (println "server running in port 3000")))

examples/just-coercion-with-ring/src/example/spec.clj

@@ -0,0 +1,23 @@
+(ns example.spec
+  (:require [clojure.spec.alpha :as s]
+            [spec-tools.spec :as spec]
+            [reitit.ring.coercion :as coercion]
+            [reitit.ring.coercion.spec :as spec-coercion]
+            [example.server :as server]))
+
+;; wrap into Spec Records to enable runtime conforming
+(s/def ::x spec/int?)
+(s/def ::y spec/int?)
+(s/def ::request (s/keys :req-un [::x ::y]))
+
+;; read coerced parameters under :parameters
+(defn handler [{{{:keys [x y]} :query} :parameters}]
+  {:status 200
+   :body {:result (+ x y)
+          :source :spec}})
+
+(def app
+  (-> #'handler
+      (server/wrap-coercion
+        {:parameters {:query ::request}
+         :coercion spec-coercion/coercion})))