Declare and check for suffixed attribute 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
# File lib/active_record/attribute_methods.rb, line 46 def attribute_method_suffix(*suffixes) attribute_method_suffixes.concat suffixes rebuild_attribute_method_regexp end
Returns true if the provided attribute is being cached.
# File lib/active_record/attribute_methods.rb, line 125 def cache_attribute?(attr_name) cached_attributes.include?(attr_name) 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).
# File lib/active_record/attribute_methods.rb, line 113 def cache_attributes(*attribute_names) attribute_names.each {|attr| cached_attributes << attr.to_s} end
Returns the attributes which are cached. By default time related columns with datatype :datetime, :timestamp, :time, :date are cached.
# File lib/active_record/attribute_methods.rb, line 119 def cached_attributes @cached_attributes ||= columns.select{|c| attribute_types_cached_by_default.include?(c.type)}.map(&:name).to_set end
Generates all the attribute related methods for columns in the database accessors, mutators and query methods.
# File lib/active_record/attribute_methods.rb, line 69 def define_attribute_methods return if generated_methods? columns_hash.each do |name, column| unless instance_method_already_implemented?(name) if self.serialized_attributes[name] define_read_method_for_serialized_attribute(name) elsif create_time_zone_conversion_attribute?(name, column) define_read_method_for_time_zone_conversion(name) else define_read_method(name.to_sym, name, column) end end unless instance_method_already_implemented?("#{name}=") if create_time_zone_conversion_attribute?(name, column) define_write_method_for_time_zone_conversion(name) else define_write_method(name.to_sym) end end unless instance_method_already_implemented?("#{name}?") define_question_method(name) end end end
# File lib/active_record/attribute_methods.rb, line 63 def generated_methods? !generated_methods.empty? 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.
# File lib/active_record/attribute_methods.rb, line 99 def instance_method_already_implemented?(method_name) method_name = method_name.to_s return true if method_name =~ /^id(=$|\?$|$)/ @_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 @@_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 raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name) @_defined_class_methods.include?(method_name) end
Returns MatchData if method_name is an attribute method.
# File lib/active_record/attribute_methods.rb, line 52 def match_attribute_method?(method_name) rebuild_attribute_method_regexp unless defined?(@@attribute_method_regexp) && @@attribute_method_regexp @@attribute_method_regexp.match(method_name) end
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