declarative_authorization Gem not working on JSON/XML requests

A little new to Rails. Im currently using rails 4.1.8 with the declarative_authorization gem. When i call one of my protected URL's from a standard browser i get the expected 'not authorized' error that i i programed into the system. If i call the same url from Postman i get my data.

Somehow it seems that Rails is ignoring declarative_authorization, or its just won't work with anything that has a header set to anything other then accept text/html.

My code is as follows: sample controller. I'm using filter_access_to :all

class ShiftsController < ApplicationController
protect_from_forgery with: :null_session 
filter_access_to :all

 def index
     qrtStr = 'shift_date between :from and :end'
     if params.has_key?(:from)
       parm = {:from => params[:from]}
     else
       parm = {:from => (Time.now.midnight - 30.day)}
     end

in authorization_rules.rb:

authorization do

role :superadmin do
  has_omnipotence
end

role :admin do
end

role :guest do
  has_permission_on :user_sessions, :to => [:new, :create]
end
role :calendarUser do
  includes :baseUser
  has_permission_on :shifts, :to => [:index, :show]
  has_permission_on :calendar, :to => [:index]
end

routes.rb:

resources :shifts, except: [:new, :edit] do
  patch 'submit', on: :member
  patch 'acquire', on: :member
end

what am i missing?? or does declarative_authorization not work correctly with rails 4.1.8??

many thanks

Their .travis.yml shows that they're only testing against Ruby 1.8.7 and 1.9.3, if you're using a newer ruby then you're in the land of the unknown. You'll do better to find a more actively maintained gem.