RingWeb Apps in Idiomatic Clojure

Mark McGranaghan

January 23, 2010

About Mark

I Bowdoin College ’10

I Clojure user since 2008

I Open source: http://github.com/mmcgrana

Motivation for Ring

I Abstract HTTP

I Write apps in idiomatic Clojure

I Share code across web frameworks

I Deploy on a variety of web servers

I WSGI & Rack

Motivation for Ring

I Abstract HTTP

I Write apps in idiomatic Clojure

I Share code across web frameworks

I Deploy on a variety of web servers

I WSGI & Rack

Motivation for Ring

I Abstract HTTP

I Write apps in idiomatic Clojure

I Share code across web frameworks

I Deploy on a variety of web servers

I WSGI & Rack

Motivation for Ring

I Abstract HTTP

I Write apps in idiomatic Clojure

I Share code across web frameworks

I Deploy on a variety of web servers

I WSGI & Rack

Motivation for Ring

I Abstract HTTP

I Write apps in idiomatic Clojure

I Share code across web frameworks

I Deploy on a variety of web servers

I WSGI & Rack

Motivation for Ring

I Abstract HTTP

I Write apps in idiomatic Clojure

I Share code across web frameworks

I Deploy on a variety of web servers

I WSGI & Rack

The Ring Project

I Spec

I Library

I Ecosystem

The Ring Project

I Spec

I Library

I Ecosystem

The Ring Project

I Spec

I Library

I Ecosystem

The Ring Project

I Spec

I Library

I Ecosystem

Overview of Ring

I Handlers are functions

I that take requests as Clojure maps

I and return responses as Clojure map

I Adapters run handlers on a web server

I Middleware augments handlers

Overview of Ring

I Handlers are functions

I that take requests as Clojure maps

I and return responses as Clojure map

I Adapters run handlers on a web server

I Middleware augments handlers

Overview of Ring

I Handlers are functions

I that take requests as Clojure maps

I and return responses as Clojure map

I Adapters run handlers on a web server

I Middleware augments handlers

Overview of Ring

I Handlers are functions

I that take requests as Clojure maps

I and return responses as Clojure map

I Adapters run handlers on a web server

I Middleware augments handlers

Overview of Ring

I Handlers are functions

I that take requests as Clojure maps

I and return responses as Clojure map

I Adapters run handlers on a web server

I Middleware augments handlers

Overview of Ring

I Handlers are functions

I that take requests as Clojure maps

I and return responses as Clojure map

I Adapters run handlers on a web server

I Middleware augments handlers

“Ring”

Request Map

{:uri <String>

:query-string <String>

:request-method <Keyword>

:headers <IPersistentMap>

:body <InputStream>

... ...}

Response Map

{:status <Integer>

:headers <IPersistentMap>

:body <String, ISeq, File, InputStream>}

Example: Hello World

(defn app [req]

{:status 200

:headers {"Content-Type" "text/html"}

:body (str "Hi from " (:server-name req))})

(use ’ring.adapter.jetty)

(run-jetty app {:port 8080})

Example: Hello World

(defn app [req]

{:status 200

:headers {"Content-Type" "text/html"}

:body (str "Hi from " (:server-name req))})

(use ’ring.adapter.jetty)

(run-jetty app {:port 8080})

Example: Hello World

Example: Stacktraces

(defn app [req]

("o noes"))

(use ’ring.adapter.jetty)

(use ’ring.middleware.stacktrace)

(run-jetty (wrap-stacktrace app) {:port 8080})

Example: Stacktraces

(defn app [req]

("o noes"))

(use ’ring.adapter.jetty)

(use ’ring.middleware.stacktrace)

(run-jetty (wrap-stacktrace app) {:port 8080})

Example: Stacktraces

Example: Static Files

(defn dynamic-app [req]

(...))

(use ’ring.middleware.file)

(use ’ring.middleware.file-info)

(def app

(-> dynamic-app

(wrap-file "public")

(wrap-file-info)))

Example: Static Files

(defn dynamic-app [req]

(...))

(use ’ring.middleware.file)

(use ’ring.middleware.file-info)

(def app

(-> dynamic-app

(wrap-file "public")

(wrap-file-info)))

Example: Testability

(defn my-app [req]

(...))

(deftest not-found-error

(let [req {:uri "/bogus/uri"}

resp (my-app req)]

(is (= 404 (:status resp)))))

Example: Testability

(defn my-app [req]

(...))

(deftest not-found-error

(let [req {:uri "/bogus/uri"}

resp (my-app req)]

(is (= 404 (:status resp)))))

Example: Testability

(defn my-app [req]

(...))

(deftest not-found-error

(let [req {:uri "/bogus/uri"}

resp (my-app req)]

(is (= 404 (:status resp)))))

Ring and Web Frameworks

I Foundation, not replacement

I Avoid duplication and share code

I Compojure, Conjure, Weld all targeting Ring

I Compojure case study

Ring and Web Frameworks

I Foundation, not replacement

I Avoid duplication and share code

I Compojure, Conjure, Weld all targeting Ring

I Compojure case study

Ring and Web Frameworks

I Foundation, not replacement

I Avoid duplication and share code

I Compojure, Conjure, Weld all targeting Ring

I Compojure case study

Ring and Web Frameworks

I Foundation, not replacement

I Avoid duplication and share code

I Compojure, Conjure, Weld all targeting Ring

I Compojure case study

Ring and Web Frameworks

I Foundation, not replacement

I Avoid duplication and share code

I Compojure, Conjure, Weld all targeting Ring

I Compojure case study

Ring Middleware

I ring.middleware.reload: Automaticallyreload namespaces

I ring.middleware.params: Get requestparams as a map

I ring.middleware.cookies: Cookie jarabstraction

Ring Middleware

I ring.middleware.reload: Automaticallyreload namespaces

I ring.middleware.params: Get requestparams as a map

I ring.middleware.cookies: Cookie jarabstraction

Ring Middleware

I ring.middleware.reload: Automaticallyreload namespaces

I ring.middleware.params: Get requestparams as a map

I ring.middleware.cookies: Cookie jarabstraction

Ring Middleware

I ring.middleware.reload: Automaticallyreload namespaces

I ring.middleware.params: Get requestparams as a map

I ring.middleware.cookies: Cookie jarabstraction

Other Components

I ring.util.servlet: If you really want aServlet

I ring.adapter.httpcore: Adapter for HTTPCore library

I ring.handler.dump: See the request map

I ring.examples.*: Runnable examples

Other Components

I ring.util.servlet: If you really want aServlet

I ring.adapter.httpcore: Adapter for HTTPCore library

I ring.handler.dump: See the request map

I ring.examples.*: Runnable examples

Other Components

I ring.util.servlet: If you really want aServlet

I ring.adapter.httpcore: Adapter for HTTPCore library

I ring.handler.dump: See the request map

I ring.examples.*: Runnable examples

Other Components

I ring.util.servlet: If you really want aServlet

I ring.adapter.httpcore: Adapter for HTTPCore library

I ring.handler.dump: See the request map

I ring.examples.*: Runnable examples

Other Components

I ring.util.servlet: If you really want aServlet

I ring.adapter.httpcore: Adapter for HTTPCore library

I ring.handler.dump: See the request map

I ring.examples.*: Runnable examples

Future Work

I Middleware and utility extraction fromframeworks

I Not a framework itself

I More use in production?

I User needs?

Future Work

I Middleware and utility extraction fromframeworks

I Not a framework itself

I More use in production?

I User needs?

Future Work

I Middleware and utility extraction fromframeworks

I Not a framework itself

I More use in production?

I User needs?

Future Work

I Middleware and utility extraction fromframeworks

I Not a framework itself

I More use in production?

I User needs?

Future Work

I Middleware and utility extraction fromframeworks

I Not a framework itself

I More use in production?

I User needs?

Learn More

I http://github.com/mmcgrana/ring

I ring/example/*.clj

I ring/SPEC