Ability to handle incoming JSON in the body

lib/grape/middleware/base.rb

@@ -1,3 +1,5 @@
+require 'multi_json'
+
 module Grape
   module Middleware
     class Base
@@ -53,11 +55,18 @@ module Formats
           :json => :encode_json,
           :txt => :encode_txt,
         }
+        PARSERS = {
+          :json => :decode_json
+        }
 
         def formatters
           FORMATTERS.merge(options[:formatters] || {})
         end
 
+        def parsers
+          PARSERS.merge(options[:parsers] || {})
+        end
+
         def content_types
           CONTENT_TYPES.merge(options[:content_types] || {})
         end
@@ -82,6 +91,35 @@ def formatter_for(api_format)
           end
         end
 
+        def parser_for(api_format)
+          spec = parsers[api_format]
+          case spec
+          when nil
+            nil
+          when Symbol
+            method(spec)
+          else
+            spec
+          end
+        end
+
+        def decode_json(object)
+          MultiJson.decode(object)
+        end
+
+        def encode_json(object)
+          if object.respond_to? :serializable_hash
+            MultiJson.encode(object.serializable_hash)
+          elsif object.respond_to? :to_json
+            object.to_json
+          else
+            MultiJson.encode(object)
+          end
+        end
+
+        def encode_txt(object)
+          object.respond_to?(:to_txt) ? object.to_txt : object.to_s
+        end
       end
 
     end

lib/grape/middleware/formatter.rb

@@ -1,5 +1,4 @@
 require 'grape/middleware/base'
-require 'multi_json'
 
 module Grape
   module Middleware
@@ -10,7 +9,8 @@ def default_options
         { 
           :default_format => :txt,
           :formatters => {},
-          :content_types => {}
+          :content_types => {},
+          :parsers => {}
         }
       end
 
@@ -22,7 +22,20 @@ def before
         fmt = format_from_extension || format_from_header || options[:default_format]
 
         if content_types.key?(fmt)
-          env['api.format'] = fmt          
+          if !env['rack.input'].nil? and (body = env['rack.input'].read).strip.length != 0
+            parser = parser_for fmt
+            unless parser.nil?
+              begin
+                body = parser.call(body)
+                env['rack.request.form_hash'] = !env['rack.request.form_hash'].nil? ? env['rack.request.form_hash'].merge(body) : body
+                env['rack.request.form_input'] = env['rack.input']
+              rescue
+                # It's possible that it's just regular POST content -- just back off
+              end
+            end
+            env['rack.input'].rewind
+          end
+          env['api.format'] = fmt
         else
           throw :error, :status => 406, :message => 'The requested format is not supported.'
         end
@@ -69,20 +82,6 @@ def after
         headers['Content-Type'] = content_types[env['api.format']]
         Rack::Response.new(bodymap, status, headers).to_a
       end
-
-      def encode_json(object)
-        if object.respond_to? :serializable_hash
-          MultiJson.encode(object.serializable_hash)
-        elsif object.respond_to? :to_json
-          object.to_json
-        else
-          MultiJson.encode(object)
-        end
-      end
-
-      def encode_txt(object)
-        object.respond_to?(:to_txt) ? object.to_txt : object.to_s
-      end
     end
   end
 end

spec/grape/middleware/formatter_spec.rb

@@ -123,4 +123,16 @@ def serializable_hash
       body.body.should == ['CUSTOM JSON FORMAT']
     end
   end
+
+  context 'Input' do
+    it 'should parse the body from a POST/PUT and put the contents into rack.request.form_hash' do
+      subject.call({'PATH_INFO' => '/info', 'Accept' => 'application/json', 'rack.input' => StringIO.new('{"is_boolean":true,"string":"thing"}')})
+      subject.env['rack.request.form_hash']['is_boolean'].should be_true
+      subject.env['rack.request.form_hash']['string'].should == 'thing'
+    end
+    it 'should be able to fail gracefully if the body is regular POST content' do
+      subject.call({'PATH_INFO' => '/info', 'Accept' => 'application/json', 'rack.input' => StringIO.new('name=Other+Test+Thing')})
+      subject.env['rack.request.form_hash'].should be_nil
+    end
+  end
 end