Invoking body false will return a blank body with 204 No Content.

CHANGELOG.md

@@ -17,6 +17,7 @@
 * [#824](https://github.com/intridea/grape/pull/824): Validate array params against list of acceptable values - [@dnd](https://github.com/dnd).
 * [#813](https://github.com/intridea/grape/pull/813): Routing methods dsl refactored to get rid of explicit `paths` parameter - [@AlexYankee](https://github.com/AlexYankee).
 * [#826](https://github.com/intridea/grape/pull/826): Find `coerce_type` for `Array` when not specified - [@manovotn](https://github.com/manovotn).
+* [#645](https://github.com/intridea/grape/issues/645): Invoking `body false` will return `204 No Content` - [@dblock](https://github.com/dblock).
 * Your contribution here.
 
 0.9.0 (8/27/2014)

README.md

@@ -54,6 +54,7 @@
   - [Hypermedia](#hypermedia)
   - [Rabl](#rabl)
   - [Active Model Serializers](#active-model-serializers)
+- [Sending Raw or No Data](#sending-raw-data)
 - [Authentication](#authentication)
 - [Describing and Inspecting an API](#describing-and-inspecting-an-api)
 - [Current Route and Endpoint](#current-route-and-endpoint)
@@ -1886,6 +1887,32 @@ You can use [Active Model Serializers](https://github.com/rails-api/active_model
 [grape-active_model_serializers](https://github.com/jrhe/grape-active_model_serializers) gem, which defines a custom Grape AMS
 formatter.
 
+## Sending Raw or No Data
+
+In general, use the binary format to send raw data.
+
+```ruby
+class API < Grape::API
+  get '/file' do
+    content_type 'application/octet-stream'
+    File.binread 'file.bin'
+  end
+end
+```
+
+You can also set the response body explicitly with `body`.
+
+```ruby
+class API < Grape::API
+  get '/' do
+    content_type 'text/plain'
+    body 'Hello World'
+    # return value ignored
+  end
+end
+```
+
+Use `body false` to return `204 No Content` without any data or content-type.
 
 ## Authentication
 

lib/grape/dsl/inside_route.rb

@@ -150,6 +150,9 @@ def cookies
       def body(value = nil)
         if value
           @body = value
+        elsif value == false
+          @body = ''
+          status 204
         else
           @body
         end

spec/grape/api_spec.rb

@@ -2726,4 +2726,33 @@ def before
       expect(last_response.body).to eq("{\"error\":\"The requested format 'txt' is not supported.\"}")
     end
   end
+
+  context 'body' do
+    context 'false' do
+      before do
+        subject.get '/blank' do
+          body false
+        end
+      end
+      it 'returns blank body' do
+        get '/blank'
+        expect(last_response.status).to eq(204)
+        expect(last_response.body).to be_blank
+      end
+    end
+    context 'plain text' do
+      before do
+        subject.get '/text' do
+          content_type 'text/plain'
+          body 'Hello World'
+          'ignored'
+        end
+      end
+      it 'returns blank body' do
+        get '/text'
+        expect(last_response.status).to eq(200)
+        expect(last_response.body).to eq 'Hello World'
+      end
+    end
+  end
 end

spec/grape/dsl/inside_route_spec.rb

@@ -160,6 +160,17 @@ def initialize
           end
         end
 
+        describe 'false' do
+          before do
+            subject.body false
+          end
+
+          it 'sets status to 204' do
+            expect(subject.body).to eq ''
+            expect(subject.status).to eq 204
+          end
+        end
+
         it 'returns default' do
           expect(subject.body).to be nil
         end