Method: ActionCable::Server::Configuration#pubsub_adapter

Defined in:
actioncable/lib/action_cable/server/configuration.rb

#pubsub_adapter ⇒ Object

Returns constant of subscription adapter specified in config/cable.yml. If the adapter cannot be found, this will default to the Redis adapter. Also makes sure proper dependencies are required.



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# File 'actioncable/lib/action_cable/server/configuration.rb', line 40

def pubsub_adapter
  adapter = (cable.fetch("adapter") { "redis" })

  # Require the adapter itself and give useful feedback about
  #     1. Missing adapter gems and
  #     2. Adapter gems' missing dependencies.
  path_to_adapter = "action_cable/subscription_adapter/#{adapter}"
  begin
    require path_to_adapter
  rescue LoadError => e
    # We couldn't require the adapter itself. Raise an exception that points out
    # config typos and missing gems.
    if e.path == path_to_adapter
      # We can assume that a non-builtin adapter was specified, so it's either
      # misspelled or missing from Gemfile.
      raise e.class, "Could not load the '#{adapter}' Action Cable pubsub adapter. Ensure that the adapter is spelled correctly in config/cable.yml and that you've added the necessary adapter gem to your Gemfile.", e.backtrace

    # Bubbled up from the adapter require. Prefix the exception message with some
    # guidance about how to address it and reraise.
    else
      raise e.class, "Error loading the '#{adapter}' Action Cable pubsub adapter. Missing a gem it depends on? #{e.message}", e.backtrace
    end
  end

  adapter = adapter.camelize
  adapter = "PostgreSQL" if adapter == "Postgresql"
  "ActionCable::SubscriptionAdapter::#{adapter}".constantize
end