My Clojure, Ring, Compojure development setup

I had to search several sources (like this) to get this setup, so I thought it would be useful to summarize my setup here. Unlike most developers, I use five different editors (emacs+slime+swank, IntelliJ IDE, GEdit, e, and Textmate) depending on which computer and OS I am on. I wanted to be able to leave a Compojure based web app running in development mode and have source files refresh regardless of which editor I am using. In the following example, I have two Clojure source files: one with Ring and Compojure code, and one a utility file, containing for this example an extremely useful function foo. Start by creating an empty Leiningen project:
lein new KBSportal
cd KBSportal
Then edit project.clj to look like:
(defproject kbsportal "0.1.0"
:description "test using Compojure for KBSportal.com"
:dependencies
[[compojure "0.4.0-SNAPSHOT"]
[ring/ring-devel "0.2.0-RC2"]
[ring/ring-httpcore-adapter "0.2.0-RC2"]
[ring/ring-jetty-adapter "0.2.0-RC2"]
[ring/ring-servlet "0.2.0-RC2"]]
:main kbsportal)
In the empty src directory create the file kbsportal.clj:
(ns kbsportal
(:use compojure.core
ring.adapter.jetty)
(:use ring.middleware.reload)
(:use ring.middleware.stacktrace)
(:use nlp)) ; nlp.clj is my other source file

(defroutes test-routes
(GET "/" []
(str "<h1>Testing foo: " (foo) "</h1>"))
(ANY "*" []
{:status 404, :body "<h1>Page not found error</h1>"}))

(def app
(-> (var test-routes)
(wrap-reload '(kbsportal))
(wrap-reload '(nlp))
(wrap-stacktrace)))

(defn dev []
(run-jetty #'app {:port 8080}))
and the file nlp.clj:
(ns nlp)

(defn foo [] " - This is from foo.") ; a very useful function!
Notice how I use the Ring wrap-reload function to force checking the date stamp on the two source files and reload them if they are changed. You would not want to check for automatic reloads in a production environment. This is a skeleton project, but in a real project you could add wrap-reload calls for new source files that you add to your project's src directory. To run in development mode, you can type:
lein repl
to start a Clojure repla and then inside the repla load the main source file and run the (dev) function:
(use 'kbsportal)
(dev)
Hit the URL http://localhost:8080 to load the test web page, edit either source file, and reload the web page to see the effects of your edits. This setup provides a quick and effective interactive development environment. If you just use emacs, then for a better alternative look for one of the excellent emacs+slime+swank Compojure-specific tutorials on the web.

Comments

  1. Thanks for this article. I started my first leiningen/compojure project now. :-)

    ReplyDelete

Post a Comment

Popular posts from this blog

My Dad's work with Robert Oppenheimer and Edward Teller

Time and Attention Fragmentation in Our Digital Lives

Ruby Sinatra web apps with background work threads