Fixed issue #690 - API call /api/v1/online_notifications/{id} yields "no route".

app/controllers/online_notifications_controller.rb

@@ -58,6 +58,33 @@ curl http://localhost/api/v1/online_notifications.json -v -u #{login}:#{password
 
 =begin
 
+Resource:
+GET /api/v1/online_notifications/{id}
+
+Payload:
+{
+  "id": "123",
+}
+
+Response:
+{
+  "id": 1,
+  "name": "some_name",
+  ...
+}
+
+Test:
+curl http://localhost/api/v1/online_notifications/#{id} -v -u #{login}:#{password}
+
+=end
+
+  def show
+    return if !access?
+    model_show_render(OnlineNotification, params)
+  end
+
+=begin
+
 Resource:
 PUT /api/v1/online_notifications/{id}
 

config/routes/online_notification.rb

@@ -3,6 +3,7 @@ Zammad::Application.routes.draw do
 
   # groups
   match api_path + '/online_notifications',                   to: 'online_notifications#index',            via: :get
+  match api_path + '/online_notifications/:id',               to: 'online_notifications#show',             via: :get
   match api_path + '/online_notifications/:id',               to: 'online_notifications#update',           via: :put
   match api_path + '/online_notifications/:id',               to: 'online_notifications#destroy',          via: :delete
   match api_path + '/online_notifications/mark_all_as_read',  to: 'online_notifications#mark_all_as_read', via: :post