Declare and check for suffixed attribute methods.

Methods
Public Instance methods
attribute_method_suffix(*suffixes)

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

[ show source ]

    # File 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
cache_attribute?(attr_name)

Returns true if the provided attribute is being cached.

[ show source ]

     # File activerecord/lib/active_record/attribute_methods.rb, line 125
125:       def cache_attribute?(attr_name)
126:         cached_attributes.include?(attr_name)
127:       end
cache_attributes(*attribute_names)

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).

[ show source ]

     # File activerecord/lib/active_record/attribute_methods.rb, line 113
113:       def cache_attributes(*attribute_names)
114:         attribute_names.each {|attr| cached_attributes << attr.to_s}
115:       end
cached_attributes()

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

[ show source ]

     # File activerecord/lib/active_record/attribute_methods.rb, line 119
119:       def cached_attributes
120:         @cached_attributes ||=
121:           columns.select{|c| attribute_types_cached_by_default.include?(c.type)}.map(&:name).to_set
122:       end
define_attribute_methods()

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

This method is also aliased as define_read_methods

[ show source ]

    # File 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 create_time_zone_conversion_attribute?(name, column)
84:               define_write_method_for_time_zone_conversion(name)
85:             else  
86:               define_write_method(name.to_sym)
87:             end
88:           end
89: 
90:           unless instance_method_already_implemented?("#{name}?")
91:             define_question_method(name)
92:           end
93:         end
94:       end
define_read_methods()

Alias for define_attribute_methods

generated_methods?()

[ show source ]

    # File activerecord/lib/active_record/attribute_methods.rb, line 63
63:       def generated_methods?
64:         !generated_methods.empty?
65:       end
instance_method_already_implemented?(method_name)

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.

[ show source ]

     # File activerecord/lib/active_record/attribute_methods.rb, line 99
 99:       def instance_method_already_implemented?(method_name)
100:         method_name = method_name.to_s
101:         return true if method_name =~ /^id(=$|\?$|$)/
102:         @_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
103:         @@_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
104:         raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name)
105:         @_defined_class_methods.include?(method_name)
106:       end
match_attribute_method?(method_name)

Returns MatchData if method_name is an attribute method.

[ show source ]

    # File 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