ruby on rails 4 - undefined method `attr_accessible' with Mongoid -

i using rails 4.1.1, ruby 2.1, mongodb, mongoid wrapper, rails_admin creating admin interfaces

i know 'attr_accessible' no longer works rails4. have installed 'protected_attributes' gem. still no success still getting warning in console

[railsadmin] not load model company, assuming model non existing. (undefined method `attr_accessible' company:class) 

so, rails admin not load class company because have defined attr_accessible in model. here company model.

  class company   include mongoid::document    @@employees_strength = {0 => '0-10', 1 => '11-50', 2 => '51-100', 3 => '101-500', 4 => '501-1000', 5 => '1000+', 6 => '5000+'}    field :name,          type: string   field :website,       type: string   field :domain_name,   type: string   field :strength,      type: integer    has_many :employees   has_one :admin, :class_name => 'employee',  :dependent => :destroy, :inverse_of => :organization    #attr_accessible :name, :website, :domain_name, :strength#, :admin_attributes, :allow_destroy => true   attr_accessible :admin_attributes   accepts_nested_attributes_for :admin, :allow_destroy => true  end 

please can body can help? thanks

mongoid 4 (<= 4.0.2 @ time of writing) not know activemodel::massassignmentsecurity module provided protected_attributes gem.

as such must include behaviour in models manually e.g.

class somedocument   include mongoid::document   include activemodel::massassignmentsecurity    field :some_field   attr_accessible :some_field end 

however, gets tedious pretty reasonable alternative include module mongoid::document module before of models defined.

module mongoid   module document     include activemodel::massassignmentsecurity   end end