An asset pipeline implementation for Sinatra based on Sprockets. sinatra-asset-pipeline supports both compiling assets on the fly for development as well as precompiling assets for production. The design goal for sinatra-asset-pipeline is to provide good defaults for integrating your Sinatra application with Sprockets.

Install Sinatra Asset Pipeline from RubyGems:

gem install sinatra-asset-pipeline

Or, include it in your project's Gemfile:

gem 'sinatra-asset-pipeline', '~> 2.2.0'

Add the provided Rake tasks to your applications Rakefile:

require 'sinatra/asset_pipeline/task'
require './app'

Sinatra::AssetPipeline::Task.define! App

This makes your application serve assets inside assets folder under the public /assets path. You can use the helpers provided by sprocket-helpers inside your assets to ease locating your assets.

During deployment of your application you can use precompile rake task to precompile your assets to serve them as static files from your applications public folder.

RACK_ENV=production rake assets:precompile

To leverage the Sprockets preprocessor pipeline inside your app you can use the assets_js_compressor and assets_css_compressor settings respectively. See the Using Processors section of the Sprockets readme for details.

If your application runs Sinatra in classic style you can define your Rake tasks as follows:

Sinatra::AssetPipeline::Task.define! Sinatra::Application

In its most simple form, you just register the Sinatra::AssetPipeline Sinatra extension within your application:

require 'sinatra/asset_pipeline'

class App < Sinatra::Base
  register Sinatra::AssetPipeline

  get '/' do
    'hi'
  end
end

However, if your application doesn't follow the defaults you can customize it as follows:

require 'sinatra/asset_pipeline'

class App < Sinatra::Base
  # Include these files when precompiling assets
  set :assets_precompile, %w(app.js app.css *.png *.jpg *.svg *.eot *.ttf *.woff *.woff2)

  # The path to your assets
  set :assets_paths, %w(assets)

  # Use another host for serving assets
  set :assets_host, '<id>.cloudfront.net'

  # Which prefix to serve the assets under
  set :assets_prefix, 'custom-prefix'

  # Serve assets using this protocol (http, :https, :relative)
  set :assets_protocol, :http

  # CSS minification
  set :assets_css_compressor, :sass

  # JavaScript minification
  set :assets_js_compressor, :uglifier

  # Register the AssetPipeline extension, make sure this goes after all customization
  register Sinatra::AssetPipeline
  
  # If you need more environments
  set :precompiled_environments, %i(staging uat production)

  get '/' do
    'hi'
  end
end