Setup Slim on Sinatra

Sintra is a light web server that's easy to start writing Ruby on. Coming from Node/Express, I feel quite at home there. Slim also feels like another JavaScript-world templating language, Jade, that I've had good experiences with. Slim makes for quick templating and feels quite nice compared to ERB if you can handle the Haml style. It's likewise quick and easy to get working on Sinatra.

Slim templates

Quick Sinatra Setup

Require Sinatra

Sinatra is super easy to setup. Create a Gemfile with the dependencies as follows:

source ""

gem "sinatra"
gem "thin"

Then create a default web.rb webserver with contents that look something like:

require "sinatra"

get "/" do
  "Hello, world!"

Then if you run the command:

$ ruby web.rb

You should get a startup message like:

== Sinatra/1.3.4 has taken the stage on 4567 for development with backup from Thin
>> Thin web server (v1.5.0 codename Knife)
>> Maximum connections set to 1024
>> Listening on, CTRL+C to stop

Go to localhost:4567 in your browser to try out your server.

Require Slim

Returning a string is all well and good, but let's include Slim to be able to create more sophisticated templates. Include your Slim dependency in your Gemfile with the line:

gem "slim"

Then from the Terminal, run:

$ bundle install

Setup your Views

Then create a directory next to your web.rb file called views. Inside views, you can create your templates. You can create a layout template aptly named layout.slim. By default, your templates will extend from this layout. Most simply, these files might look like this:


doctype html
    title My Slim Templates App
    == yield

And, index.slim:

h1 Loving Slim

Serve a Slim File

And now to adjust our web.rb file to serve the new index.slim file:

require "sinatra"
require "slim"

get "/" do
  slim :index

Finally restart your server, and you should see your new template shown in all it's glory. Pretty easy cheesy.

Setup Slim on Rails

Want something even easier? Well, if you know Rails already, this will be a cinch. The hardest part of getting Slim running on Rails is Rails itself. Slim integration is even easier than on Sinatra. Simply add this line to your Gemfile:

gem "slim-rails"

And then in order to activate the Slim handler, merely add the .slim extension onto the end of any of your template file names. Your file names probably end in .erb by default. Change the ones that you want to convert to Slim templates to look like:


Now the Rails are even slicker.