Description¶ ↑

Determines which model attributes in a Hash of parameters can be set via mass-assignment.

Example¶ ↑

Say we have this model:

class User < ActiveRecord::Base
  attr_accessible :username, password
end

And these parameters for creating a new User:

params = {
  :username         => 'bob123',
  :password         => 'secret',
  :hashed_password  => 'd6c1fbcf028923cc0480fff4ab459a21',
  }

If that “params” Hash was used to create a new User:

@user = User.new params

an exception would be raised, because the ‘hashed_password’ attribute is not settable via mass-assignment.

The solution is to extract the “accessible” attributes from the “params” Hash, like this:

accessible_params = AccessibleModelAttributes.extract User, params
@user = User.new accessible_params

The “accessible_params” variable will contain this:

{:username => 'bob123', password => 'secret'}