[SOLVED] Ember Engines inside Rails Engines via ember-cli-rails

Ember Engines inside Rails Engines via ember-cli-rails

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?

Solution

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.