Component integration

Component

Stuert Sierra's Component is a great library for managing the stateful resources of your app. There are several strategies to use it. Here are some samples how to use Component with compojure-api:

Using closures

This is the preferred way as we are not littering the request.

(defn more-routes [db]
  (routes
    (GET "/ping" []
      (ok {:ping (str "I have a db: " db)}))))

(defn create [{:keys [db] :as system}]
  (api
    (GET "/user/:id" []
      :path-params [id :- s/Str]
      (ok (get-user db id))
    (more-routes db))))

Injecting component via request

Use either :components-option of api-middleware or wrap-components-middleware to associate the components with your API.

Components can be read from the request using compojure.api.middleware/get-components or using the :components restucturing with letk-syntax.

(require '[compojure.api.middleware :as mw])

(defroutes more-routes
  (GET "/ping" []
    :components [db]
    (ok {:ping (str "I have a db: " db)})))

(defapi handler
  (GET "/user/:id" []
    :path-params [id :- s/Str]
    :components [db]
    (ok (get-user db id)))
  more-routes)

(defn app (mw/wrap-components handler (create-system))

(defroutes more-routes
  (GET "/ping" []
    :components [db]
    (ok {:ping (str "I have a db: " db)})))

(defapi app
  {:components (create-system)}
  (GET "/user/:id" []
    :path-params [id :- s/Str]
    :components [db]
    (ok (get-user db id)))
  more-routes)

To see this in action, try lein run and navigate to Components api group.