Ember Engines inside Rails Engines via ember-cli-rails

Question

We have a high modular rails5 app, which is splitted in rails engines over serveral repositories and integrated as ruby gems.

Now we want to introduce EmberJS by using ember-cli-rails. The main rails application contains the main ember application in the frontend directory while each of the rails engines contain an ember engine (via ember-engine) in a frontend directory.

How to mount the ember engines of the modules into the main ember engine?

Answer 1

Due the fact that I've found no other solution so far, I've created an initializer which symlinks the ember engine directories of all rails engines into the node_modules of the consuming ember engine in the consuming rails app:

# Get the node_modules dir
nm_dir = Rails.root.join('frontend', 'node_modules')

# Delete existing symlinks
Dir.new(nm_dir.to_s).each { |entry| FileUtils.rm_rf(entry) if entry =~ /^.+\-frontend$/ }

# MODULES contains an array of the rails engine gem names
MODULES.each do |module_name|
  # Each module has a Manifest class, load that
  manifest = load_manifest(module_name)

  # Get the path to the frontend dir of the rails engine
  source = Pathname.new(manifest.method(:setup).source_location[0].split('/lib/')[0]).join('frontend').to_s

  # Symlink destination
  destination = nm_dir.join("#{module_name}-frontend").to_s

  # Symlink it
  FileUtils.symlink source, destination, force: true
end

This approach is probably not very clean, but it seems to work.