/api/version route; exposes API semantic version

app/openbel/api/app.rb

@@ -15,12 +15,13 @@
 require_relative 'routes/base'
 require_relative 'routes/root'
 require_relative 'routes/annotations'
-require_relative 'routes/nanopubs'
+require_relative 'routes/authenticate'
 require_relative 'routes/datasets'
 require_relative 'routes/expressions'
 require_relative 'routes/language'
 require_relative 'routes/namespaces'
-require_relative 'routes/authenticate'
+require_relative 'routes/nanopubs'
+require_relative 'routes/version'
 require_relative 'middleware/auth'
 
 module OpenBEL
@@ -72,6 +73,7 @@ class Server < Sinatra::Application
     use OpenBEL::Routes::Expressions
     use OpenBEL::Routes::Language
     use OpenBEL::Routes::Namespaces
+    use OpenBEL::Routes::Version
 
     # routes requiring authentication
     if OpenBEL::Settings[:auth][:enabled]

app/openbel/api/routes/version.rb

@@ -0,0 +1,63 @@
+require 'openbel/api/version'
+
+module OpenBEL
+  module Routes
+    # Version defines and implements the _/api/version_ route that exposes
+    # the semantic version of the OpenBEL API.
+    class Version < Base
+
+      JSON             = Rack::Mime.mime_type('.json')
+      HAL              = 'application/hal+json'
+      TEXT             = Rack::Mime.mime_type('.txt')
+      ACCEPTED_TYPES   = {
+        'hal'  => HAL,
+        'json' => JSON,
+        'text' => TEXT
+      }
+      DEFAULT_TYPE     = TEXT
+
+      helpers do
+        def requested_media_type
+          if params && params[:format]
+            ACCEPTED_TYPES[params[:format]]
+          else
+            request.accept.flat_map { |accept_entry|
+              ACCEPTED_TYPES.values.find { |type| type == accept_entry.entry }
+            }.compact.first
+          end
+        end
+      end
+
+      options '/api/version' do
+        response.headers['Allow'] = 'OPTIONS,GET'
+        status 200
+      end
+
+      get '/api/version' do
+        accept_type = requested_media_type || DEFAULT_TYPE
+
+        case accept_type
+        when TEXT
+          response.headers['Content-Type'] = 'text/plain'
+          OpenBEL::Version.to_s
+        when HAL, JSON
+          response.headers['Content-Type'] = 'application/hal+json'
+          MultiJson.dump({
+            :version => {
+              :string => OpenBEL::Version.to_s,
+              :semantic_version => {
+                :major => OpenBEL::Version::MAJOR,
+                :minor => OpenBEL::Version::MINOR,
+                :patch => OpenBEL::Version::PATCH
+              }
+            }
+          })
+        else
+          halt 406
+        end
+      end
+    end
+  end
+end
+# vim: ts=2 sw=2:
+# encoding: utf-8