Enable routing & implement handlers (clj)

minimal-api-clj.core/deps.edn

@@ -1,6 +1,8 @@
 {:paths ["resources" "src"]
- :deps {camel-snake-kebab {:mvn/version "0.4.0"}
+ :deps {bidi {:mvn/version "2.1.6"}
+        camel-snake-kebab {:mvn/version "0.4.0"}
         integrant {:mvn/version "0.7.0"}
+        metosin/ring-http-response {:mvn/version "0.9.1"}
         org.clojure/clojure {:mvn/version "1.10.0"}
         ring/ring-core {:mvn/version "1.7.1"}
         ring/ring-jetty-adapter {:mvn/version "1.7.1"}

minimal-api-clj.core/src/minimal_api_clj/core.clj

@@ -1,21 +1,61 @@
 (ns minimal-api-clj.core
   (:gen-class)
-  (:require [camel-snake-kebab.core :refer [->kebab-case ->snake_case]]
+  (:require [bidi.ring :refer [make-handler]]
+            [camel-snake-kebab.core :refer [->kebab-case ->snake_case]]
             [camel-snake-kebab.extras :refer [transform-keys]]
+            [clojure.string :as str]
             [integrant.core :as ig]
             [ring.adapter.jetty :as jetty]
             [ring.middleware.json :refer [wrap-json-params wrap-json-response]]
             [ring.middleware.keyword-params :refer [wrap-keyword-params]]
             [ring.middleware.params :refer [wrap-params]]
-            [ring.util.response :as response]))
+            [ring.util.http-response :as response]))
 
 ;;; handlers
 
-(defn hello-world [request]
-  ;; for debug
-  (clojure.pprint/pprint (:params request))
-  (response/response {:message "Hello, World!"
-                      :params (:params request)}))
+(def todos
+  (atom {"todo1" {"task" "build an API"}
+         "todo2" {"task" "?????"}
+         "todo3" {"task" "profit!"}}))
+
+(defn list-todos [_]
+  (response/ok @todos))
+
+(defn create-todo [{:keys [params]}]
+  (let [id (->> (keys @todos)
+                (map #(-> %
+                          (str/replace-first "todo" "")
+                          Long/parseLong))
+                (apply max)
+                inc)
+        todo-id (str "todo" id)]
+    (swap! todos assoc todo-id {"task" (:task params)})
+    (response/created (str "/todos/" todo-id) (get @todos todo-id))))
+
+(defn fetch-todo [{:keys [params]}]
+  (if-let [todo (get @todos (:todo-id params))]
+    (response/ok todo)
+    (response/not-found {:message (str "Todo " (:todo-id params) " doesn't exist")})))
+
+(defn delete-todo [{:keys [params]}]
+  (if (get @todos (:todo-id params))
+    (do (swap! todos dissoc (:todo-id params))
+        (response/no-content))
+    (response/not-found {:message (str "Todo " (:todo-id params) " doesn't exist")})))
+
+(defn update-todo [{:keys [params]}]
+  (let [task {"task" (:task params)}]
+    (swap! todos assoc (:todo-id params) task)
+    (response/created (str "/todos/" (:todo-id params)) task)))
+
+;;; routes
+
+(defmethod ig/init-key ::routes [_ _]
+  ["/" {"todos" {:get list-todos
+                 :post create-todo}
+        ["todos/" :todo-id] {:get fetch-todo
+                             :delete delete-todo
+                             :put update-todo}}])
 
 ;;; middleware
 
@@ -26,8 +66,8 @@
                        handler)]
       (transform-keys #(->snake_case % :separator \-) response))))
 
-(defmethod ig/init-key ::app [_ _]
-  (-> hello-world
+(defmethod ig/init-key ::app [_ {:keys [routes]}]
+  (-> (make-handler routes)
       wrap-kebab-case-keys
       wrap-keyword-params
       wrap-json-params
@@ -45,7 +85,8 @@
 ;;; system configuration
 
 (def config
-  {::app {}
+  {::routes {}
+   ::app {:routes (ig/ref ::routes)}
    ::server {:app (ig/ref ::app)
              :options {:port 3000
                        :join? false}}})