Allow routing concerns to accept a callable

This allows us to make alterations to the generated routes based on the
scope of the current mapper, and otherwise allows us to move larger
blocks of concerns out of the routes file, altogether.

1 files changed, 7 insertions, 3 deletions

diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index b52f66faf1..b1abbbe505 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -1613,8 +1613,8 @@ module ActionDispatch
         #   end
         #
         # Any routing helpers can be used inside a concern.
-        def concern(name, &block)
-          @concerns[name] = block
+        def concern(name, callable = nil, &block)
+          @concerns[name] = callable || block
         end
 
         # Use the named concerns
@@ -1631,7 +1631,7 @@ module ActionDispatch
         def concerns(*names)
           names.flatten.each do |name|
             if concern = @concerns[name]
-              instance_eval(&concern)
+              concern.call(self)
             else
               raise ArgumentError, "No concern named #{name} was found!"
             end
@@ -1645,6 +1645,10 @@ module ActionDispatch
         @concerns = {}
       end
 
+      def current_scope
+        @scope
+      end
+
       include Base
       include HttpHelpers
       include Redirection