Module ActiveRecord::AttributeMethods::ClassMethods
In: vendor/rails/activerecord/lib/active_record/attribute_methods.rb

Declare and check for suffixed attribute methods.

Methods

Public Instance methods

Declares a method available for all attributes with the given suffix. Uses method_missing and respond_to? to rewrite the method

  #{attr}#{suffix}(*args, &block)

to

  attribute#{suffix}(#{attr}, *args, &block)

An attribute#{suffix} instance method must exist and accept at least the attr argument.

For example:

  class Person < ActiveRecord::Base
    attribute_method_suffix '_changed?'

    private
      def attribute_changed?(attr)
        ...
      end
  end

  person = Person.find(1)
  person.name_changed?    # => false
  person.name = 'Hubert'
  person.name_changed?    # => true

[Source]

    # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 46
46:       def attribute_method_suffix(*suffixes)
47:         attribute_method_suffixes.concat suffixes
48:         rebuild_attribute_method_regexp
49:       end

Returns true if the provided attribute is being cached.

[Source]

     # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 127
127:       def cache_attribute?(attr_name)
128:         cached_attributes.include?(attr_name)
129:       end

cache_attributes allows you to declare which converted attribute values should be cached. Usually caching only pays off for attributes with expensive conversion methods, like time related columns (e.g. created_at, updated_at).

[Source]

     # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 115
115:       def cache_attributes(*attribute_names)
116:         attribute_names.each {|attr| cached_attributes << attr.to_s}
117:       end

Returns the attributes which are cached. By default time related columns with datatype :datetime, :timestamp, :time, :date are cached.

[Source]

     # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 121
121:       def cached_attributes
122:         @cached_attributes ||=
123:           columns.select{|c| attribute_types_cached_by_default.include?(c.type)}.map(&:name).to_set
124:       end

Generates all the attribute related methods for columns in the database accessors, mutators and query methods.

[Source]

    # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 69
69:       def define_attribute_methods
70:         return if generated_methods?
71:         columns_hash.each do |name, column|
72:           unless instance_method_already_implemented?(name)
73:             if self.serialized_attributes[name]
74:               define_read_method_for_serialized_attribute(name)
75:             elsif create_time_zone_conversion_attribute?(name, column)
76:               define_read_method_for_time_zone_conversion(name)
77:             else
78:               define_read_method(name.to_sym, name, column)
79:             end
80:           end
81: 
82:           unless instance_method_already_implemented?("#{name}=")
83:             if self.serialized_attributes[name]
84:               define_write_method_for_serialized_attribute(name)
85:             elsif create_time_zone_conversion_attribute?(name, column)
86:               define_write_method_for_time_zone_conversion(name)
87:             else  
88:               define_write_method(name.to_sym)
89:             end
90:           end
91: 
92:           unless instance_method_already_implemented?("#{name}?")
93:             define_question_method(name)
94:           end
95:         end
96:       end
define_read_methods()

[Source]

    # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 63
63:       def generated_methods?
64:         !generated_methods.empty?
65:       end

Checks whether the method is defined in the model or any of its subclasses that also derive from Active Record. Raises DangerousAttributeError if the method is defined by Active Record though.

[Source]

     # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 101
101:       def instance_method_already_implemented?(method_name)
102:         method_name = method_name.to_s
103:         return true if method_name =~ /^id(=$|\?$|$)/
104:         @_defined_class_methods         ||= ancestors.first(ancestors.index(ActiveRecord::Base)).sum([]) { |m| m.public_instance_methods(false) | m.private_instance_methods(false) | m.protected_instance_methods(false) }.map(&:to_s).to_set
105:         @@_defined_activerecord_methods ||= (ActiveRecord::Base.public_instance_methods(false) | ActiveRecord::Base.private_instance_methods(false) | ActiveRecord::Base.protected_instance_methods(false)).map(&:to_s).to_set
106:         raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name)
107:         @_defined_class_methods.include?(method_name)
108:       end

Returns MatchData if method_name is an attribute method.

[Source]

    # File vendor/rails/activerecord/lib/active_record/attribute_methods.rb, line 52
52:       def match_attribute_method?(method_name)
53:         rebuild_attribute_method_regexp unless defined?(@@attribute_method_regexp) && @@attribute_method_regexp
54:         @@attribute_method_regexp.match(method_name)
55:       end

[Validate]