Add specs and example for multiple strategies

README.markdown

@@ -117,6 +117,32 @@ MyApi::Application.routes.draw do
 end
 ```
 
+### Using Multiple Strategies
+
+It is possible to combine two or more of the above strategies. One
+example of when you might want to support multiple strategies
+simultaneously is if you have an API that supports JSONP. Your preferred
+strategy might be for users of the API to set a header, but since JSONP
+doesn't support setting custom headers, you also need to support either
+:path or :parameter.
+
+Example:
+
+```ruby
+MyApi::Application.routes.draw do
+  api_version(:module => 'V2', :header => 'API-VERSION', :parameter => "version", :value => 'v2', :path => 'v2') do
+    match '/foos.(:format)' => 'foos#index', :via => :get
+    match '/foos_no_format' => 'foos#index', :via => :get
+    resources :bars
+  end
+end
+```
+
+Caveat: If you are using :header and :parameter, they need to share the
+same value. For this reason, if you use mupltiple strategies, you will
+probably want to set a custom header instead of using an Accept mime
+type.
+
 ### Default Version
 
 If a request is made to your API without specifying a specific version, by default a RoutingError (i.e. 404) will occur. You can optionally configure Versionist to

spec/api_routing_spec.rb

@@ -632,6 +632,38 @@
             end
           end
         end
+
+        context "multi strategy" do
+          before :each do
+            TestApi::Application.routes.draw do
+              api_version({:module => mod, :header => "API-VERSION", :parameter => "version", :path => ver, :value => ver}) do
+                match '/foos.(:format)' => 'foos#index', :via => :get
+              end
+            end
+          end
+
+          it "should route to the correct controller when header matches" do
+            @headers["HTTP_API_VERSION"] = ver
+            get "/foos.json", nil, @headers
+            assert_response 200
+            assert_equal 'application/json', response.content_type
+            assert_equal ver, response.body
+          end
+
+          it "should route to the correct controller when path matches" do
+            get "/#{ver}/foos.json", nil, @headers
+            assert_response 200
+            assert_equal 'application/json', response.content_type
+            assert_equal ver, response.body
+          end
+
+          it "should route to the correct controller when parameter matches" do
+            get "/foos.json?version=#{ver}", nil, @headers
+            assert_response 200
+            assert_equal 'application/json', response.content_type
+            assert_equal ver, response.body
+          end
+        end
       end
     end
   end