purgecss_sprockets

PurgeCSS Sprockets

Reduce CSS file size by removing unused selectors with PurgeCSS in Rails asset pipeline.

Installation

Ruby Gem

Add this line to your application's Gemfile:

gem 'purgecss_sprockets'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install purgecss_sprockets

JS library

Install PurgeCSS in your Rails application if you don't have it:

$ yarn add purgecss

Run the config file generator:

$ rails g purgecss_sprockets:install

Usage

This gem is intended to be used as a post processor step in your asset pipeline:

$ bundle exec rake assets:precompile

You can temporarily disable the processor or re-configure how PurgeCSS is called in an initializer:

config/initializers/purgecss_sprockets.rb:

PurgecssSprockets.disabled = true # default: false
PurgecssSprockets.purgecss_cmd = "node node_modules/purgecss/bin/purgecss.js"

You can exclude some entrypoints by filling the exclude_files in the initializer:

PurgecssSprockets.exclude_files = %w(
  app/assets/stylesheets/admin.sass
)

You can configure PurgeCSS with the generated purgecss.config.js.

Debug

• In an initializer, disable the PurgecssSprockets' post-processor.
• Run rails assets:clobber assets:precompile
• Open a Rails console and run this:

  json = JSON.parse(`node node_modules/purgecss/bin/purgecss.js --css public/assets/[your-digested-css-file].css --config purgecss.config.js --rejected`)[0]
  

• You can now check which selectors are rejected by PurgeCSS in json['rejected'].

Development

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/noesya/purgecss_sprockets. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the PurgeCSS Sprockets project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.