Don't use config option for flashing_formats

lib/devise.rb

@@ -209,10 +209,6 @@ module Devise
   mattr_accessor :navigational_formats
   @@navigational_formats = ["*/*", :html]
 
-  # Which formats should display flash messages.
-  mattr_accessor :flashing_formats
-  @@flashing_formats = nil
-
   # When set to true, signing out a user signs out all other scopes.
   mattr_accessor :sign_out_all_scopes
   @@sign_out_all_scopes = true

lib/devise/controllers/helpers.rb

@@ -291,8 +291,10 @@ module Devise
         Devise.navigational_formats.include?(request_format)
       end
 
+      # Check if flash messages should be emitted. Default is to do it on
+      # navigational formats
       def is_flashing_format?
-        (Devise.flashing_formats || Devise.navigational_formats).include?(request_format)
+        is_navigational_format?
       end
 
       private

lib/generators/templates/devise.rb

@@ -221,10 +221,6 @@ Devise.setup do |config|
   # The "*/*" below is required to match Internet Explorer requests.
   # config.navigational_formats = ['*/*', :html]
 
-  # Lists the formats that should display flash messages. Inherits
-  # navigational_formats if falsy
-  # config.flashing_formats = nil
-
   # The default HTTP method used to sign out a resource. Default is :delete.
   config.sign_out_via = :delete
 

test/rails_app/config/initializers/devise.rb

@@ -162,10 +162,6 @@ Devise.setup do |config|
   # should add them to the navigational formats lists. Default is [:html]
   # config.navigational_formats = [:html, :iphone]
 
-  # Lists the formats that should display flash messages. Inherits
-  # navigational_formats if falsy
-  # config.flashing_formats = nil
-
   # The default HTTP method used to sign out a resource. Default is :get.
   # config.sign_out_via = :get