Cuba is probably one of the tiniest rack-based micro frameworks around. Weighing in at only 138 LOC, it has proven itself to be a very resilient tool in various web application domains. Check the list of sites built using Cuba in order to grasp the endless possibilities.
Cuba does one thing, and it does it well. Cuba-contrib, on the other hand, layers requirement-specific functionality on top of it. This allows us to build simpler and lighter solutions.
To get started with Cuba::Contrib, install it using RubyGems:
$ gem install cuba # if you haven't already done so
$ gem install cuba-contribFor the remainder of the examples below, we'll assume you
always put your main cuba application in app.rb and your
views in views.
$ touch app.rb
$ mkdir viewsNow you can require it in your application
require "cuba"
require "cuba/contrib"
Cuba.plugin Cuba::PreludeCuba::Prelude adds the basic stuff you'll need:
Cuba.define do
on "about" do
# same as encodeURIComponent in javascript land
res.write urlencode("http://www.google.com")
# basically an alias for Rack::Utils.escape_html
res.write h("Cuba & Cuba Contrib")
end
endWe prefer to use our home-grown templating engine called
Mote. We do that by simply loading the plugin Cuba::Mote:
require "cuba"
require "cuba/contrib"
Cuba.plugin Cuba::Mote
Cuba.define do
on "home" do
res.write view("home")
end
on "about" do
res.write partial("about")
end
endThis assumes that you have a views folder, containing a home.mote
and an about.mote.
require "cuba"
require "cuba/contrib"
Cuba.plugin Cuba::Rendering
Cuba.set :template_engine, "haml"
Cuba.define do
on "home" do
res.write view("home") # renders views/home.haml
end
on "about" do
res.write partial("about") # renders views/about.haml
end
endAuthoring your own plugins is pretty straightforward.
module MyOwnHelper
def markdown(str)
BlueCloth.new(str).to_html
end
end
Cuba.plugin MyOwnHelperthat's the simplest kind of plugin you'll write. In fact,
that's exactly how the markdown helper is written in
Cuba::TextHelpers.
A more complicated plugin for example, will make use of
Cuba.settings to provide default values:
module Rendering
def self.setup(app)
app.settings[:template_engine] = "erb"
end
def partial(template, locals = {})
render("#{template}.#{settings[:template_engine]}", locals)
end
end
Cuba.plugin RenderingThis sample plugin actually resembles how Cuba::Rendering works.