lib/RestFailureApp.rb
class RestFailureApp < Devise::FailureApp
def respond
if !request.format.blank? && request.format.to_s.include?('json')
json_failure
else
super
end
end
def json_failure
self.status = 401
self.content_type = 'application/json'
self.response_body = Api::SessionsController.fail_login_info('Authentication error.',nil).to_json
end
end