Asset precompilation from an Engine's initializer

gistfile1.rb

### RAILS 4.1

# Doesn't work, due to the error:
# Asset filtered out and will not be served: add 
# `Rails.application.config.assets.precompile += %w( refinery/refinery.css )` 
# to `config/initializers/assets.rb` and restart your server

class MyEngine < Rails::Engine
  # set the manifests and assets to be precompiled
  initializer "refinery.assets.precompile" do |app|
    app.config.assets.precompile += %w(
      refinery/*
      refinery/icons/*
      wymeditor/lang/*
      wymeditor/skins/refinery/*
      wymeditor/skins/refinery/**/*
      modernizr-min.js
      admin.js
    )
  end
end

# Works:

class MyEngine < Rails::Engine
  # set the manifests and assets to be precompiled
  config.to_prepare do
    Rails.application.config.assets.precompile += %w(
      refinery/*
      refinery/icons/*
      wymeditor/lang/*
      wymeditor/skins/refinery/*
      wymeditor/skins/refinery/**/*
      modernizr-min.js
      admin.js
    )
  end
end

Thanks for this. I should point out that you should only include the manifest if you're using a manifest to load the rest of the stylesheets/javascripts. I didn't get it right the first because I used /* instead of including the manifest explicitly. That resulted in loading everything with no regards to the load order specified in the manifest.