Module ActiveModel::MassAssignmentSecurity::ClassMethods
In: lib/active_model/mass_assignment_security.rb

Mass assignment security provides an interface for protecting attributes from end-user assignment. For more complex permissions, mass assignment security may be handled outside the model by extending a non-ActiveRecord class, such as a controller, with this behavior.

For example, a logged in user may need to assign additional attributes depending on their role:

class AccountsController < ApplicationController

  include ActiveModel::MassAssignmentSecurity

  attr_accessible :first_name, :last_name

  def self.admin_accessible_attributes
    accessible_attributes + [ :plan_id ]
  end

  def update
    ...
    @account.update_attributes(account_params)
    ...
  end

  protected

  def account_params
    sanitize_for_mass_assignment(params[:account])
  end

  def mass_assignment_authorizer
    admin ? admin_accessible_attributes : super
  end

end

Methods

Public Instance methods

Specifies a white list of model attributes that can be set via mass-assignment.

This is the opposite of the attr_protected macro: Mass-assignment will only set attributes in this list, to assign to the rest of attributes you can use direct writer methods. This is meant to protect sensitive attributes from being overwritten by malicious users tampering with URLs or forms. If you‘d rather start from an all-open default and restrict attributes as needed, have a look at attr_protected.

  class Customer
    include ActiveModel::MassAssignmentSecurity

    attr_accessor :name, :credit_rating
    attr_accessible :name

    def attributes=(values)
      sanitize_for_mass_assignment(values).each do |k, v|
        send("#{k}=", v)
      end
    end
  end

  customer = Customer.new
  customer.attributes = { :name => "David", :credit_rating => "Excellent" }
  customer.name          # => "David"
  customer.credit_rating # => nil

  customer.credit_rating = "Average"
  customer.credit_rating # => "Average"

Note that using Hash#except or Hash#slice in place of attr_accessible to sanitize attributes won‘t provide sufficient protection.

Attributes named in this macro are protected from mass-assignment whenever attributes are sanitized before assignment.

Mass-assignment to these attributes will simply be ignored, to assign to them you can use direct writer methods. This is meant to protect sensitive attributes from being overwritten by malicious users tampering with URLs or forms.

Example

  class Customer
    include ActiveModel::MassAssignmentSecurity

    attr_accessor :name, :credit_rating
    attr_protected :credit_rating

    def attributes=(values)
      sanitize_for_mass_assignment(values).each do |k, v|
        send("#{k}=", v)
      end
    end
  end

  customer = Customer.new
  customer.attributes = { "name" => "David", "credit_rating" => "Excellent" }
  customer.name          # => "David"
  customer.credit_rating # => nil

  customer.credit_rating = "Average"
  customer.credit_rating # => "Average"

To start from an all-closed default and enable attributes as needed, have a look at attr_accessible.

Note that using Hash#except or Hash#slice in place of attr_protected to sanitize attributes won‘t provide sufficient protection.

[Validate]