1 files changed, 60 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/middleware/params_parser.rb b/actionpack/lib/action_dispatch/middleware/params_parser.rb
new file mode 100644
index 0000000000..b426183488
--- /dev/null
+++ b/actionpack/lib/action_dispatch/middleware/params_parser.rb
@@ -0,0 +1,60 @@
+require 'active_support/core_ext/hash/conversions'
+require 'action_dispatch/http/request'
+require 'active_support/core_ext/hash/indifferent_access'
+
+module ActionDispatch
+  class ParamsParser
+    class ParseError < StandardError
+      attr_reader :original_exception
+
+      def initialize(message, original_exception)
+        super(message)
+        @original_exception = original_exception
+      end
+    end
+
+    DEFAULT_PARSERS = { Mime::JSON => :json }
+
+    def initialize(app, parsers = {})
+      @app, @parsers = app, DEFAULT_PARSERS.merge(parsers)
+    end
+
+    def call(env)
+      if params = parse_formatted_parameters(env)
+        env["action_dispatch.request.request_parameters"] = params
+      end
+
+      @app.call(env)
+    end
+
+    private
+      def parse_formatted_parameters(env)
+        request = Request.new(env)
+
+        return false if request.content_length.zero?
+
+        strategy = @parsers[request.content_mime_type]
+
+        return false unless strategy
+
+        case strategy
+        when Proc
+          strategy.call(request.raw_post)
+        when :json
+          data = ActiveSupport::JSON.decode(request.raw_post)
+          data = {:_json => data} unless data.is_a?(Hash)
+          Request::Utils.deep_munge(data).with_indifferent_access
+        else
+          false
+        end
+      rescue Exception => e # JSON or Ruby code block errors
+        logger(env).debug "Error occurred while parsing request parameters.\nContents:\n\n#{request.raw_post}"
+
+        raise ParseError.new(e.message, e)
+      end
+
+      def logger(env)
+        env['action_dispatch.logger'] || ActiveSupport::Logger.new($stderr)
+      end
+  end
+end