On Rails 4 raise unknown compressor: csso.

As I understand in Rails 4 we need to register CSS comperssor in Rails app for a instance Sprockets::Environment, like:

initializer "csso.environment", :after => "sprockets.environment" do
  CssCompressor.install(app.assets)
end

class CssCompressor
  def install(sprockets)
    sprockets.register_compressor('text/css', :csso, 'Csso::CssCompressor')
  end
end

After this fix, error doesn’t raise, but CssCompressor#compress didn’t be called. So we need more research (I will research later, after accept another pull request, because it is easy to research on non-Rails Sprockets env).

undefined method `new' for #<Csso::Compressor:0x007fe39f85e3e8>
.bundle/gems/sprockets-3.0.0/lib/sprockets/legacy_tilt_processor.rb:25:in `call'

/cc @Vasfed

RubyGems.org doesn't report a license for your gem. This is because it is not specified in the gemspec of your last release.

via e.g.

spec.license = 'MIT'
# or
spec.licenses = ['MIT', 'GPL-2']

Including a license in your gemspec is an easy way for rubygems.org and other tools to check how your gem is licensed. As you can imagine, scanning your repository for a LICENSE file or parsing the README, and then attempting to identify the license or licenses is much more difficult and more error prone. So, even for projects that already specify a license, including a license in your gemspec is a good practice. See, for example, how rubygems.org uses the gemspec to display the rails gem license.

There is even a License Finder gem to help companies/individuals ensure all gems they use meet their licensing needs. This tool depends on license information being available in the gemspec. This is an important enough issue that even Bundler now generates gems with a default 'MIT' license.

I hope you'll consider specifying a license in your gemspec. If not, please just close the issue with a nice message. In either case, I'll follow up. Thanks for your time!

Appendix:

If you need help choosing a license (sorry, I haven't checked your readme or looked for a license file), GitHub has created a license picker tool. Code without a license specified defaults to 'All rights reserved'-- denying others all rights to use of the code.
Here's a list of the license names I've found and their frequencies

p.s. In case you're wondering how I found you and why I made this issue, it's because I'm collecting stats on gems (I was originally looking for download data) and decided to collect license metadata,too, and make issues for gemspecs not specifying a license as a public service :). See the previous link or my blog post about this project for more information.

We need csso version in code or README.md to check is csso-rails is actual.

Can we get this gem updated to support the latest csso v5 library? Thanks.

@Vasfed

NameError: uninitialized constant Sprockets::Compressors
/home/ai/Dev/amplifr/.bundle/gems/csso-rails-0.4.0/lib/csso.rb:16:in `install'
/home/ai/Dev/amplifr/.bundle/gems/csso-rails-0.4.0/lib/csso/railtie.rb:7:in `block in <class:Railtie>'

/cc @Vasfed

Gem therubyracer is not a only way to execute JS. For example, in some projects we have JRuby, so we can use only therubyrhino.

Will be better to use execjs in dependencies to use any avaiable JS engine.

Is csso packed in gem latest? Maybe we need some small script to easy pick lastest csso from it repo? Maybe we can use git submodules?

What is a difference between stock csso and packed in your gem?

Hey, I'm using Node.js via ExecJS and it gives me this error.

You're using ExecJS::ExternalRuntime, did you forget to add therubyracer or other execjs runtime to gemfile?

Can we disable the warning since ExecJS will raise an error if no engine is found?

CSSO is a best compressor. Maybe we should suggest it to Sporockets by default? I will support your issue.

Current version is 1.3.10

whether it is possible to include support for the creation of source maps?

Current csso repo is css/csso, not afelix/csso like in README.md.

I'd like to see if this is even working but I can't seem to figure it out. I've followed the installation instructions. I've added therubyracer as well (not sure why this is needed exactly) and have even put...

config.assets.compress = true
config.assets.css_compressor = :csso

...in all of my config/environments, as well as config/application.rb, but I have yet to see it actually compressing anything.

Sorry, I'm a Rails newb but really enjoy CSSO and would love to get this working in tandem with Autoprefixer. :)

When optimizing a CSS file.

And csso.js contains this line:

case null:console.warn("[csstree-match] BREAK after "+os+" iterations")

The warn function is missing here:

console = {
  log: function(){},
  error: function(txt){
    throw txt;
  }
};

Gem::LoadError on line ["1990"] of /Users//.rvm/rubies/ruby-2.0.0-p195/lib/ruby/site_ruby/2.0.0/rubygems/specification.rb: Unable to activate csso-rails-0.3.0, because execjs-2.0.1 conflicts with execjs (> 1.4)
Run with --trace to see the full backtrace

Users that have execjs (2.0.1) throw this error despite both being installed. Can csso-rails be updated to execjs 2.0.1 or is there a way to use either version that may be available?

I get a fatal error using the csso gem:

I'm using Rails 3.2 and including csso with:

config.assets.css_compressor = :csso