How to get the list of all engines in Rails 3 app

Question

According to Rails engines extending functionality in Rails 2.x one could do

Rails::Initializer.new(Rails.configuration).plugin_loader.engines

This code is not working in Rails 3

ActionController::RoutingError (undefined method `new' for Rails::Initializer:Module):
  config/application.rb:12:in `require_or_load'

What do I need to do in Rails 3 to get such list of engines?

This is needed for Extending controllers of a Rails 3 Engine in the main app

Darren Hicks · Answer 1 · 2014-05-16T18:40:46.680

17

This has changed with Rails 4.1. The accepted answer is deprecated and the new way to get the installed Engines for a Rails application is now:

::Rails::Engine.subclasses.map(&:instance)

Here's a reference to the commit in github making the change (and also showing how it was implemented after initial deprecation...)

If you need to use the previous solution from Rails 4.1:

module Rails
    class Engine
        class Railties
            def self.engines
                @engines ||= Rails::Engine.subclasses.map(&:instance)
            end
        end
    end
end

edited May 16 '14 at 18:40

answered May 16 '14 at 18:16

Darren Hicks

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Yes - the question was for a Rails 3 app, but it is still misleading to stumble upon this answer without the latest and greatest having a presence. – Darren Hicks May 16 '14 at 18:42

score 13 · Accepted Answer · answered May 11 '11 at 00:00

13

As of 5/10/2011 and Rails 3.1 beta, it's now

Rails::Application::Railties.engines

answered May 11 '11 at 00:00

Jeremy Raines

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score 2 · Answer 3 · answered Feb 19 '11 at 08:13

2

Try:

Rails::Application.railties.engines

answered Feb 19 '11 at 08:13

Adrian Pacala

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great, it works! Could you also advise me how I can get directory of the engine? – Andrei Feb 19 '11 at 08:34
2

Ok, I've found it: `Rails::Application.railties.engines.first.config.root` – Andrei Feb 19 '11 at 08:42

How to get the list of all engines in Rails 3 app

3 Answers3

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