Move the permissions call out of api_controller

app/controllers/api/permissions_controller.rb

@@ -0,0 +1,27 @@
+module Api
+  class PermissionsController < ApplicationController
+    skip_before_action :verify_authenticity_token
+    before_action :api_deny_access_handler
+
+    authorize_resource :class => false
+
+    before_action :check_api_readable
+    before_action :setup_user_auth
+    around_action :api_call_handle_error, :api_call_timeout
+
+    # External apps that use the api are able to query which permissions
+    # they have. This currently returns a list of permissions granted to the current user:
+    # * if authenticated via OAuth, this list will contain all permissions granted by the user to the access_token.
+    # * if authenticated via basic auth all permissions are granted, so the list will contain all permissions.
+    # * unauthenticated users have no permissions, so the list will be empty.
+    def show
+      @permissions = if current_token.present?
+                       ClientApplication.all_permissions.select { |p| current_token.read_attribute(p) }
+                     elsif current_user
+                       ClientApplication.all_permissions
+                     else
+                       []
+                     end
+    end
+  end
+end