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Open a terminal and type lein repl to start a Clojure REPL (interactive prompt).

In the REPL, type


The call to (run) starts the Figwheel server at port 3449, which takes care of live reloading ClojureScript code and CSS. Figwheel's server will also act as your app server, so requests are correctly forwarded to the http-handler you define.

Running (browser-repl) starts the Weasel REPL server, and drops you into a ClojureScript REPL. Evaluating expressions here will only work once you've loaded the page, so the browser can connect to Weasel.

When you see the line Successfully compiled "resources/public/app.js" in 21.36 seconds., you're ready to go. Browse to http://localhost:3449 and enjoy.

Attention: It is not needed to run lein figwheel separately. Instead we launch Figwheel directly from the REPL

Trying it out

If all is well you now have a browser window saying 'Hello Chestnut', and a REPL prompt that looks like cljs.user=>.

Open resources/public/css/style.css and change some styling of the H1 element. Notice how it's updated instantly in the browser.

Open src/cljs/haxlife/core.cljs, and change dom/h1 to dom/h2. As soon as you save the file, your browser is updated.

In the REPL, type

(ns haxlife.core)
(swap! app-state assoc :text "Interactivity FTW")

Notice again how the browser updates.


Lighttable provides a tighter integration for live coding with an inline browser-tab. Rather than evaluating cljs on the command line with weasel repl, evaluate code and preview pages inside Lighttable.

Steps: After running (run), open a browser tab in Lighttable. Open a cljs file from within a project, go to the end of an s-expression and hit Cmd-ENT. Lighttable will ask you which client to connect. Click 'Connect a client' and select 'Browser'. Browse to http://localhost:3449

View LT's console to see a Chrome js console.

Hereafter, you can save a file and see changes or evaluate cljs code (without saving a file). Note that running a weasel server is not required to evaluate code in Lighttable.


Start a repl in the context of your project with M-x cider-jack-in.

Switch to repl-buffer with C-c C-z and start web and figwheel servers with (run), and weasel server with (browser-repl). Load http://localhost:3449 on an external browser, which connects to weasel, and start evaluating cljs inside Cider.

To run the Clojurescript tests, do

lein doo phantom

Deploying to Heroku

This assumes you have a Heroku account, have installed the Heroku toolbelt, and have done a heroku login before.

git init
git add -A
git commit
heroku create
git push heroku master:master
heroku open

Running with Foreman

Heroku uses Foreman to run your app, which uses the Procfile in your repository to figure out which server command to run. Heroku also compiles and runs your code with a Leiningen "production" profile, instead of "dev". To locally simulate what Heroku does you can do:

lein with-profile -dev,+production uberjar && foreman start

Now your app is running at http://localhost:5000 in production mode.


Copyright © 2016 FIXME

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.


Created with Chestnut 0.10.0-SNAPSHOT (ee1a85d5).

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