Module: HasDigest::ClassMethods

Defined in:
lib/has_digest.rb

Instance Method Summary collapse

Instance Method Details

#dependent_has_digest_attributes ⇒ Object

:nodoc:



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# File 'lib/has_digest.rb', line 122

def dependent_has_digest_attributes # :nodoc:
  has_digest_attributes.reject { |name, options| !options.has_key?(:dependencies) }
end

#has_digest(attribute, options = {}) ⇒ Object

Gives the class it is called on a before_save callback that writes a 40-character hexadecimal string into the given attribute. The generated string may depend on other (possibly synthetic) attributes of the model, being automatically regenerated when they change. One key is supported in the options hash:

  • depends: either a single attribute name or a list of attribute names. If any of these values change, attribute will be re-written. Setting any (non-synthetic) one of these attributes to nil will effectively also set attribute to nil.

Magic Salting

If the model in question has a salt attribute, its salt be automatically populated on create and automatically mixed into any digests with dependencies on other attributes, saving you a little bit of work when dealing with passwords.

Magic Synthetic Attributes

If the model in question doesn’t have a database column for one of your digest dependencies, an attr_accessor for that synthetic dependency will be created automatically. For example, if you write has_digest :encrypted_password, :depends => :password and don’t have a password column for your model, the attr_accessor for password will be automatically created, saving you a redundant line of code.

Examples

# token will be generated on create
class Order < ActiveRecord::Base
  has_digest :token
end

# encrypted_password will be generated on save whenever @password is not nil
# (Automatically calls attr_accessor :password.)
class User < ActiveRecord::Base
  has_digest :encrypted_password, :depends => :password
end

# remember_me_token will be generated on save whenever login or remember_me_until have changed.
# User.update_attributes(:remember_me_until => nil) will set remember_me_token to nil.
class User < ActiveRecord::Base
  has_digest :remember_me_token, :depends => [:login, :remember_me_until]
end

# api_token will be blank until user.update_attributes(:generate_api_token => true).
# (Automatically calls attr_accessor :generate_api_token.)
class User < ActiveRecord::Base
  has_digest :api_token, :depends => :generate_api_token
end



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# File 'lib/has_digest.rb', line 100

def has_digest(attribute, options = {})
  options.assert_valid_keys(:depends)

  if options[:depends]
    dependencies = []
    dependencies << :salt if column_names.include?('salt')
    dependencies << options[:depends]
    dependencies.flatten!

    synthetic_dependencies = dependencies - column_names.map(&:to_sym)
    synthetic_dependencies.each { |name| attr_accessor name }

    write_inheritable_hash :has_digest_attributes, attribute => { :dependencies => dependencies, :synthetic_dependencies => synthetic_dependencies }
  else
    write_inheritable_hash :has_digest_attributes, attribute => {}
  end
end

#has_digest_attributes ⇒ Object

:nodoc:



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# File 'lib/has_digest.rb', line 118

def has_digest_attributes # :nodoc:
  read_inheritable_attribute(:has_digest_attributes) || write_inheritable_attribute(:has_digest_attributes, {})
end

#standalone_has_digest_attributes ⇒ Object

:nodoc:



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# File 'lib/has_digest.rb', line 126

def standalone_has_digest_attributes # :nodoc:
  has_digest_attributes.reject { |name, options| options.has_key?(:dependencies) }
end