2 files changed, 35 insertions, 25 deletions
diff --git a/actionpack/lib/action_dispatch/http/parameters.rb b/actionpack/lib/action_dispatch/http/parameters.rb
index 3c9f8cd9e4..3867e514a2 100644
--- a/actionpack/lib/action_dispatch/http/parameters.rb
+++ b/actionpack/lib/action_dispatch/http/parameters.rb
@@ -3,6 +3,20 @@ module ActionDispatch
     module Parameters
       PARAMETERS_KEY = 'action_dispatch.request.path_parameters'
 
+      DEFAULT_PARSERS = {
+        Mime::JSON => lambda { |raw_post|
+          data = ActiveSupport::JSON.decode(raw_post)
+          data.is_a?(Hash) ? data : {:_json => data}
+        }
+      }
+
+      def self.included(klass)
+        class << klass
+          attr_accessor :parameter_parsers
+        end
+
+        klass.parameter_parsers = DEFAULT_PARSERS
+      end
       # Returns both GET and POST \parameters in a single hash.
       def parameters
         params = get_header("action_dispatch.request.parameters")
@@ -31,6 +45,27 @@ module ActionDispatch
       def path_parameters
         get_header(PARAMETERS_KEY) || {}
       end
+
+      private
+
+      def parse_formatted_parameters(request, parsers)
+        return yield if request.content_length.zero?
+
+        strategy = parsers.fetch(request.content_mime_type) { return yield }
+
+        begin
+          strategy.call(request.raw_post)
+        rescue => e # JSON or Ruby code block errors
+          my_logger = logger || ActiveSupport::Logger.new($stderr)
+          my_logger.debug "Error occurred while parsing request parameters.\nContents:\n\n#{request.raw_post}"
+
+          raise ParamsParser::ParseError.new(e.message, e)
+        end
+      end
+
+      def params_parsers
+        ActionDispatch::Request.parameter_parsers
+      end
     end
   end
 end
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index ea083425ba..cb59510613 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -361,16 +361,6 @@ module ActionDispatch
     end
     alias :request_parameters :POST
 
-    def params_parsers
-      fetch_header "action_dispatch.request.params_parsers" do
-        {}
-      end
-    end
-
-    def params_parsers= hash
-      set_header "action_dispatch.request.params_parsers", hash
-    end
-
     # Returns the authorization header regardless of whether it was specified directly or through one of the
     # proxy alternatives.
     def authorization
@@ -399,20 +389,5 @@ module ActionDispatch
         HTTP_METHOD_LOOKUP[name] || raise(ActionController::UnknownHttpMethod, "#{name}, accepted HTTP methods are #{HTTP_METHODS[0...-1].join(', ')}, and #{HTTP_METHODS[-1]}")
         name
       end
-
-    def parse_formatted_parameters(request, parsers)
-      return yield if request.content_length.zero?
-
-      strategy = parsers.fetch(request.content_mime_type) { return yield }
-
-      begin
-        strategy.call(request.raw_post)
-      rescue => e # JSON or Ruby code block errors
-        my_logger = logger || ActiveSupport::Logger.new($stderr)
-        my_logger.debug "Error occurred while parsing request parameters.\nContents:\n\n#{request.raw_post}"
-
-        raise ParamsParser::ParseError.new(e.message, e)
-      end
-    end
   end
 end