User Model roles

user.rb

require 'csv'

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable, :confirmable, :token_authenticatable,
         :recoverable, :rememberable, :trackable, :authentication_keys => [:rollno]

  

  # Roles initialization
  ROLES = [ :admin, :student, :assistant, :professor ]
  mask = {:student => [2], :admin => [1], :assistant => [4], :professor => [8] }

  
  
  scope :find_by_roles, lambda {|role| 
    u = User.where("roles_mask IN(?)", mask[role.to_sym]) #.order(:first_name)
  }

  
  def roles=(roles)
    self.roles_mask = (roles.map(&:to_sym) & User::ROLES).map { |r| 2**User::ROLES.index(r) }.sum  
    self.save
  end  

  def roles  
    User::ROLES.reject { |r| ((roles_mask || 0) & 2**User::ROLES.index(r)).zero? }  
  end

  def add_roles(*args)
    raise ArgumentError.new('You must to specify additional roles within User::ROLES.') if args.map { |role| User::ROLES.include?(role.to_sym) }.include?(false)
    args.map { |role| roles.include?(role.to_sym) ? false : self.roles = roles << role.to_sym }
    roles
  end

  def remove_roles(*args)
    if args.nil? || args.empty?
      self.update_attribute(:roles_mask, nil)
    else
      self.roles = roles.delete_if { |e| args.map(&:to_sym).include?(e) }
    end
  end
 
  def is_admin?
    ! ([:admin] & roles).blank?
  end

  def is_student?
    ! ([:student] & roles).blank?
  end

  def is_assistant?
    ! ([:assistant] & roles).blank?
  end

  def is_professor?
    ! ([:professor] & roles).blank?
  end

  def approve!
    update_attribute(:approved,true)
  end

  def deactivate!
    update_attribute(:approved,false)
  end


  # Methods for devise

  def active_for_authentication? 
    super && approved? 
  end 

  def inactive_message 
    if !approved? 
      :not_approved 
    else 
      super # Use whatever other message 
    end 
  end

  
end