Compojure-api

Stuff on top of Compojure for making sweet web apis.

• Schema & clojure.spec (2.0.0) for input & output data coercion
• Swagger for api documentation, via ring-swagger & spec-tools
• Async with async-ring, manifold and core.async (2.0.0)
• Client negotiable formats: JSON, EDN & Transit, optionally YAML and MessagePack
• Data-driven resources
• Bi-directional routing
• Bundled middleware for common api behavior (exception handling, parameters & formats)
• Extendable route DSL via metadata handlers
• Route functions & macros for putting things together, including the Swagger-UI via ring-swagger-ui
• Requires Clojure 1.9.0 & Java 1.8

API Docs & Wiki

Latest version

Latest non-alpha: [metosin/compojure-api "1.1.13"].

See CHANGELOG for details.

For information and help

Read the Version 1.0 Blog Post

Schema & Spec Coercion with 2.0.0

Check wiki for documentation

Clojurians slack (join) has a channel #ring-swagger for talk about any libraries using Ring-swagger. You can also ask questions about Compojure-api and Ring-swagger on other channels at Clojurians Slack or at #clojure on Freenode IRC (mention compojure-api or ring-swagger to highlight us).

Examples

Hello World Api

(require '[compojure.api.sweet :refer :all])
(require '[ring.util.http-response :refer :all])

(def app
  (api
    (GET "/hello" []
      :query-params [name :- String]
      (ok {:message (str "Hello, " name)}))))

Hello World, async

(require '[compojure.api.sweet :refer :all])
(require '[clojure.core.async :as a])

(GET "/hello-async" []
  :query-params [name :- String]
  (a/go
    (a/<! (a/timeout 500))
    (ok {:message (str "Hello, " name)})))

_{* requires server to be run in async mode}

Hello World, async & data-driven

(require '[compojure.api.sweet :refer :all])
(require '[clojure.core.async :as a])
(require '[schema.core :as s])

(context "/hello-async" []
  (resource
    {:get
     {:parameters {:query-params {:name String}}
      :responses {200 {:schema {:message String}}
                  404 {}
                  500 {:schema s/Any}}
      :handler (fn [{{:keys [name]} :query-params}]
                 (a/go
                   (a/<! (a/timeout 500))
                   (ok {:message (str "Hello, " name)})))}}))

_{* Note that empty body responses can be specified with {} or {:schema s/Any}}

Hello World, async, data-driven & clojure.spec

(require '[compojure.api.sweet :refer :all])
(require '[clojure.core.async :as a])
(require '[clojure.spec.alpha :as s])

(s/def ::name string?)
(s/def ::message string?)

(context "/hello-async" []
  (resource
    {:coercion :spec
     :get {:parameters {:query-params (s/keys :req-un [::name])}
           :responses {200 {:schema (s/keys :req-un [::message])}}
           :handler (fn [{{:keys [name]} :query-params}]
                      (a/go
                        (a/<! (a/timeout 500))
                        (ok {:message (str "Hello, " name)})))}}))

Api with Schema & Swagger-docs

(require '[compojure.api.sweet :refer :all])
(require '[schema.core :as s])

(s/defschema Pizza
  {:name s/Str
   (s/optional-key :description) s/Str
   :size (s/enum :L :M :S)
   :origin {:country (s/enum :FI :PO)
            :city s/Str}})

(def app
  (api
    {:swagger
     {:ui "/api-docs"
      :spec "/swagger.json"
      :data {:info {:title "Sample API"
                    :description "Compojure Api example"}
             :tags [{:name "api", :description "some apis"}]
             :consumes ["application/json"]
             :produces ["application/json"]}}}

    (context "/api" []
      :tags ["api"]

      (GET "/plus" []
        :return {:result Long}
        :query-params [x :- Long, y :- Long]
        :summary "adds two numbers together"
        (ok {:result (+ x y)}))

      (POST "/echo" []
        :return Pizza
        :body [pizza Pizza]
        :summary "echoes a Pizza"
        (ok pizza)))))

More samples

• official samples: https://github.com/metosin/compojure-api/tree/master/examples
• great full app: https://github.com/yogthos/memory-hole
• 2.0.0 sample: https://github.com/metosin/c2
• RESTful CRUD APIs Using Compojure-API and Toucan: https://www.demystifyfp.com/clojure/blog/restful-crud-apis-using-compojure-api-and-toucan-part-1/
• clojurice, An opinionated starter app for full-stack web applications in Clojure: https://github.com/jarcane/clojurice
• Web Development with Clojure, Second Edition: https://pragprog.com/book/dswdcloj2/web-development-with-clojure-second-edition

To try it yourself, clone this repository and do either:

1. lein run
2. lein repl & (go)

Quick start for a new project

Use a Leiningen template, with or without tests:

lein new compojure-api my-api
lein new compojure-api my-api +midje
lein new compojure-api my-api +clojure-test

License

Copyright © 2014-2018 Metosin Oy

Distributed under the Eclipse Public License, the same as Clojure.