class Rails::Configuration::MiddlewareStackProxy

MiddlewareStackProxy is a proxy for the Rails middleware stack that allows you to configure middlewares in your application. It works basically as a command recorder, saving each command to be applied after initialization over the default middleware stack, so you can add, swap, or remove any middleware in Rails.

You can add your own middlewares by using the config.middleware.use method:

config.middleware.use Magical::Unicorns

This will put the Magical::Unicorns middleware on the end of the stack. You can use insert_before if you wish to add a middleware before another:

config.middleware.insert_before Rack::Head, Magical::Unicorns

There’s also insert_after which will insert a middleware after another:

config.middleware.insert_after Rack::Head, Magical::Unicorns

Middlewares can also be completely swapped out and replaced with others:

config.middleware.swap ActionDispatch::Flash, Magical::Unicorns

Middlewares can be moved from one place to another:

config.middleware.move_before ActionDispatch::Flash, Magical::Unicorns

This will move the Magical::Unicorns middleware before the ActionDispatch::Flash. You can also move it after:

config.middleware.move_after ActionDispatch::Flash, Magical::Unicorns

And finally they can also be removed from the stack completely:

config.middleware.delete ActionDispatch::Flash

# File railties/lib/rails/configuration.rb, line 47
def initialize(operations = [], delete_operations = [])
  @operations = operations
  @delete_operations = delete_operations
end

# File railties/lib/rails/configuration.rb, line 70
def delete(...)
  @delete_operations << -> middleware { middleware.delete(...) }
end

# File railties/lib/rails/configuration.rb, line 58
def insert_after(...)
  @operations << -> middleware { middleware.insert_after(...) }
end

# File railties/lib/rails/configuration.rb, line 52
def insert_before(...)
  @operations << -> middleware { middleware.insert_before(...) }
end

# File railties/lib/rails/configuration.rb, line 80
def move_after(...)
  @delete_operations << -> middleware { middleware.move_after(...) }
end

# File railties/lib/rails/configuration.rb, line 74
def move_before(...)
  @delete_operations << -> middleware { middleware.move_before(...) }
end

# File railties/lib/rails/configuration.rb, line 62
def swap(...)
  @operations << -> middleware { middleware.swap(...) }
end

# File railties/lib/rails/configuration.rb, line 84
def unshift(...)
  @operations << -> middleware { middleware.unshift(...) }
end

# File railties/lib/rails/configuration.rb, line 66
def use(...)
  @operations << -> middleware { middleware.use(...) }
end