Etudes for ClojureScript

Appendix D. ClojureScript on the Server

ClojureScript on the Server

Just as JavaScript works in the browser and on the server, via a library like Node.js, so does ClojureScript. In this book, I’m using Node.js for the server side.

Getting Node.js

You can get Node.js from the download page. This will also give you npm, Node’s package manager.

Creating a ClojureScript/Node.js Project

I created a project named node-project by following the instructions at the ClojureScript Quick Start page. (I am sick and tired of “Hello, world!” so I did something slightly different.)

Here is the file structure of the directory, with files organized by category rather than alphabetical order. Notice that the project name node-project has a hyphen in it, but when used in a directory name, you replace the hyphen with an underscore, node_project:

node_project
├── cljs.jar
├── src
│   └── node_project
│       └── core.cljs
└── node.clj

The cljs.jar file contains ClojureScript, downloaded from the link at the Quick Start page.

ClojureScript File src/node_project/core.cljs

This is the ClojureScript file for the project; it simply prints to the console:

(ns node-project.core
  (:require [cljs.nodejs :as nodejs]))

(nodejs/enable-util-print!)

(defn -main [& args]
  (println "It works!"))

(set! *main-cli-fn* -main)

File node.clj

This file builds the unoptimized project:

(require 'cljs.build.api)

(cljs.build.api/build "src"
  {:main 'node-project.core
   :output-to "main.js"
   :target :nodejs})

File node_repl.clj ...