Add redirect feature

README.markdown

@@ -213,6 +213,19 @@ cookies[:counter] = {
 }
 cookies[:counter][:value] +=1
 ```
+## Redirect
+
+You can redirect to a new url
+
+``` ruby
+redirect "/new_url"
+```
+
+use permanent redirect
+
+``` ruby
+redirect "/new_url", :permanent => true
+```
 
 ## Raising Errors
 

lib/grape/endpoint.rb

@@ -133,6 +133,26 @@ def error!(message, status=403)
       throw :error, :message => message, :status => status
     end
 
+    # Redirect to a new url.
+    # 
+    # @param url [String] The url to be redirect.
+    # @param options [Hash] The options used when redirect.
+    #                       :permanent, default true.
+    def redirect(url, options = {})
+      merged_options = {:permanent => false }.merge(options)
+      if merged_options[:permanent]
+        status 304
+      else
+        if env['HTTP_VERSION'] == 'HTTP/1.1' && request.request_method.to_s.upcase != "GET"
+          status 303
+        else 
+          status 302
+        end
+      end
+      header "Location", url
+      body ""
+    end
+
     # Set or retrieve the HTTP status code.
     #
     # @param status [Integer] The HTTP Status Code to return for this request.

spec/grape/endpoint_spec.rb

@@ -204,6 +204,37 @@ def app; subject end
       last_response.body.should == '{"dude":"rad"}'
     end
   end
+
+  describe "#redirect" do 
+    it "should redirect to a url with status 302" do 
+      subject.get('/hey') do 
+        redirect "/ha"
+      end
+      get '/hey'
+      last_response.status.should eq 302
+      last_response.headers['Location'].should eq "/ha"
+      last_response.body.should eq ""
+    end
+
+    it "should have status code 303 if it is not get request and it is http 1.1" do
+      subject.post('/hey') do 
+        redirect "/ha"
+      end
+      post '/hey', {}, 'HTTP_VERSION' => 'HTTP/1.1'
+      last_response.status.should eq 303
+      last_response.headers['Location'].should eq "/ha"
+    end
+
+    it "support permanent redirect" do 
+      subject.get('/hey') do 
+        redirect "/ha", :permanent => true
+      end
+      get '/hey'
+      last_response.status.should eq 304
+      last_response.headers['Location'].should eq "/ha"
+      last_response.body.should eq ""
+    end
+  end
 
   it 'should not persist params between calls' do
     subject.post('/new') do
@@ -345,4 +376,4 @@ def memoized
       end
     end
   end
-end
+end