compojure-rest example.clj

(def products-resource
     (resource 
      :method-allowed? #(some #{(% :request-method)} [:get :post])
      :content-types-provided { "text/html" :to_html, "text/plain" :to_text }
      :created (fn [_ req _] (str "Product " (add-product (slurp-body req))  " created."))
      :to_html (fn [_ req _] 
		 (html [:html
			[:head [:title "All Products"]]
			[:body [:h1 "All Products"]
			 [:ul (map (fn [p] [:li [:a { :href (p :id)} (p :title)]]) 
				   (trace "AP" (all-products)))]]]))
      :to_text (fn [_ req _]
		 (apply str (map #(str (% :id) ": " (% :title) "\n") (all-products))))))

(def product-resource
     (resource
      :method-allowed? #(some #{(% :request-method)} [:get :delete :put ])
      :content-types-provided { "text/html" :to_html, "text/plain" :to_text }
      :exists? (fn [req] (if-let [id (trace "id" (read-string (-> req :route-params :id)))]
			   (if-let [product (trace "product" (product-by-id id))]
			    { ::product product })))
      :etag    (fn [req] (str "P-" (-> req ::product :id)))
      :delete  (fn [req] (remove-product-by-id (-> req :route-params :id)))
      :entity? false
      :to_html (fn [rmap req status]
		 (let [product (req ::product)]	
		   (html [:h1 (product :id)] [:p (product :title)])))
      :to_text (fn [rmap req status]
		 (let [product (req ::product)]	
		   (str  (product :id) ": " (product :title))))))

(defroutes my-app
  (ANY "/products/"    products-resource)
  (ANY "/products/:id" product-resource)