# frozen_string_literal: true
require "mutex_m"
require "active_support/core_ext/enumerable"
module ActiveRecord
# = Active Record Attribute Methods
module AttributeMethods
extend ActiveSupport::Concern
include ActiveModel::AttributeMethods
included do
initialize_generated_modules
include Read
include Write
include BeforeTypeCast
include Query
include PrimaryKey
include TimeZoneConversion
include Dirty
include Serialization
end
RESTRICTED_CLASS_METHODS = %w(private public protected allocate new name parent superclass)
class GeneratedAttributeMethods < Module # :nodoc:
include Mutex_m
end
class << self
def dangerous_attribute_methods # :nodoc:
@dangerous_attribute_methods ||= (
Base.instance_methods +
Base.private_instance_methods -
Base.superclass.instance_methods -
Base.superclass.private_instance_methods +
%i[__id__ dup freeze frozen? hash class clone]
).map { |m| -m.to_s }.to_set.freeze
end
end
module ClassMethods
def initialize_generated_modules # :nodoc:
@generated_attribute_methods = const_set(:GeneratedAttributeMethods, GeneratedAttributeMethods.new)
private_constant :GeneratedAttributeMethods
@attribute_methods_generated = false
@alias_attributes_mass_generated = false
include @generated_attribute_methods
super
end
def alias_attribute(new_name, old_name)
super
if @alias_attributes_mass_generated
ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |code_generator|
generate_alias_attribute_methods(code_generator, new_name, old_name)
end
end
end
def eagerly_generate_alias_attribute_methods(_new_name, _old_name) # :nodoc:
# alias attributes in Active Record are lazily generated
end
def generate_alias_attributes # :nodoc:
superclass.generate_alias_attributes unless superclass == Base
return false if @alias_attributes_mass_generated
generated_attribute_methods.synchronize do
return if @alias_attributes_mass_generated
ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |code_generator|
aliases_by_attribute_name.each do |old_name, new_names|
new_names.each do |new_name|
generate_alias_attribute_methods(code_generator, new_name, old_name)
end
end
end
@alias_attributes_mass_generated = true
end
true
end
def generate_alias_attribute_methods(code_generator, new_name, old_name) # :nodoc:
attribute_method_patterns.each do |pattern|
alias_attribute_method_definition(code_generator, pattern, new_name, old_name)
end
attribute_method_patterns_cache.clear
end
def alias_attribute_method_definition(code_generator, pattern, new_name, old_name) # :nodoc:
method_name = pattern.method_name(new_name).to_s
target_name = pattern.method_name(old_name).to_s
old_name = old_name.to_s
method_defined = method_defined?(target_name) || private_method_defined?(target_name)
manually_defined = method_defined &&
!self.instance_method(target_name).owner.is_a?(GeneratedAttributeMethods)
reserved_method_name = ::ActiveRecord::AttributeMethods.dangerous_attribute_methods.include?(target_name)
if !abstract_class? && !has_attribute?(old_name)
# We only need to issue this deprecation warning once, so we issue it when defining the original reader method.
should_warn = target_name == old_name
if should_warn
ActiveRecord.deprecator.warn(
"#{self} model aliases `#{old_name}`, but `#{old_name}` is not an attribute. " \
"Starting in Rails 7.2, alias_attribute with non-attribute targets will raise. " \
"Use `alias_method :#{new_name}, :#{old_name}` or define the method manually."
)
end
super
elsif manually_defined && !reserved_method_name
aliased_method_redefined_as_well = method_defined_within?(method_name, self)
return if aliased_method_redefined_as_well
ActiveRecord.deprecator.warn(
"#{self} model aliases `#{old_name}` and has a method called `#{target_name}` defined. " \
"Starting in Rails 7.2 `#{method_name}` will not be calling `#{target_name}` anymore. " \
"You may want to additionally define `#{method_name}` to preserve the current behavior."
)
super
else
define_attribute_method_pattern(pattern, old_name, owner: code_generator, as: new_name, override: true)
end
end
# Generates all the attribute related methods for columns in the database
# accessors, mutators and query methods.
def define_attribute_methods # :nodoc:
return false if @attribute_methods_generated
# Use a mutex; we don't want two threads simultaneously trying to define
# attribute methods.
generated_attribute_methods.synchronize do
return false if @attribute_methods_generated
superclass.define_attribute_methods unless base_class?
super(attribute_names)
@attribute_methods_generated = true
end
true
end
def attribute_methods_generated? # :nodoc:
@attribute_methods_generated && @alias_attributes_mass_generated
end
def undefine_attribute_methods # :nodoc:
generated_attribute_methods.synchronize do
super if defined?(@attribute_methods_generated) && @attribute_methods_generated
@attribute_methods_generated = false
@alias_attributes_mass_generated = false
end
end
# Raises an ActiveRecord::DangerousAttributeError exception when an
# \Active \Record method is defined in the model, otherwise +false+.
#
# class Person < ActiveRecord::Base
# def save
# 'already defined by Active Record'
# end
# end
#
# Person.instance_method_already_implemented?(:save)
# # => ActiveRecord::DangerousAttributeError: save is defined by Active Record. Check to make sure that you don't have an attribute or method with the same name.
#
# Person.instance_method_already_implemented?(:name)
# # => false
def instance_method_already_implemented?(method_name)
if dangerous_attribute_method?(method_name)
raise DangerousAttributeError, "#{method_name} is defined by Active Record. Check to make sure that you don't have an attribute or method with the same name."
end
if superclass == Base
super
else
# If ThisClass < ... < SomeSuperClass < ... < Base and SomeSuperClass
# defines its own attribute method, then we don't want to override that.
defined = method_defined_within?(method_name, superclass, Base) &&
! superclass.instance_method(method_name).owner.is_a?(GeneratedAttributeMethods)
defined || super
end
end
# A method name is 'dangerous' if it is already (re)defined by Active Record, but
# not by any ancestors. (So 'puts' is not dangerous but 'save' is.)
def dangerous_attribute_method?(name) # :nodoc:
::ActiveRecord::AttributeMethods.dangerous_attribute_methods.include?(name.to_s)
end
def method_defined_within?(name, klass, superklass = klass.superclass) # :nodoc:
if klass.method_defined?(name) || klass.private_method_defined?(name)
if superklass.method_defined?(name) || superklass.private_method_defined?(name)
klass.instance_method(name).owner != superklass.instance_method(name).owner
else
true
end
else
false
end
end
# A class method is 'dangerous' if it is already (re)defined by Active Record, but
# not by any ancestors. (So 'puts' is not dangerous but 'new' is.)
def dangerous_class_method?(method_name)
return true if RESTRICTED_CLASS_METHODS.include?(method_name.to_s)
if Base.respond_to?(method_name, true)
if Object.respond_to?(method_name, true)
Base.method(method_name).owner != Object.method(method_name).owner
else
true
end
else
false
end
end
# Returns +true+ if +attribute+ is an attribute method and table exists,
# +false+ otherwise.
#
# class Person < ActiveRecord::Base
# end
#
# Person.attribute_method?('name') # => true
# Person.attribute_method?(:age=) # => true
# Person.attribute_method?(:nothing) # => false
def attribute_method?(attribute)
super || (table_exists? && column_names.include?(attribute.to_s.delete_suffix("=")))
end
# Returns an array of column names as strings if it's not an abstract class and
# table exists. Otherwise it returns an empty array.
#
# class Person < ActiveRecord::Base
# end
#
# Person.attribute_names
# # => ["id", "created_at", "updated_at", "name", "age"]
def attribute_names
@attribute_names ||= if !abstract_class? && table_exists?
attribute_types.keys
else
[]
end.freeze
end
# Returns true if the given attribute exists, otherwise false.
#
# class Person < ActiveRecord::Base
# alias_attribute :new_name, :name
# end
#
# Person.has_attribute?('name') # => true
# Person.has_attribute?('new_name') # => true
# Person.has_attribute?(:age) # => true
# Person.has_attribute?(:nothing) # => false
def has_attribute?(attr_name)
attr_name = attr_name.to_s
attr_name = attribute_aliases[attr_name] || attr_name
attribute_types.key?(attr_name)
end
def _has_attribute?(attr_name) # :nodoc:
attribute_types.key?(attr_name)
end
private
def inherited(child_class)
super
child_class.initialize_generated_modules
child_class.class_eval do
@alias_attributes_mass_generated = false
@attribute_names = nil
end
end
end
# A Person object with a name attribute can ask person.respond_to?(:name),
# person.respond_to?(:name=), and person.respond_to?(:name?)
# which will all return +true+. It also defines the attribute methods if they have
# not been generated.
#
# class Person < ActiveRecord::Base
# end
#
# person = Person.new
# person.respond_to?(:name) # => true
# person.respond_to?(:name=) # => true
# person.respond_to?(:name?) # => true
# person.respond_to?('age') # => true
# person.respond_to?('age=') # => true
# person.respond_to?('age?') # => true
# person.respond_to?(:nothing) # => false
def respond_to?(name, include_private = false)
return false unless super
# If the result is true then check for the select case.
# For queries selecting a subset of columns, return false for unselected columns.
# We check defined?(@attributes) not to issue warnings if called on objects that
# have been allocated but not yet initialized.
if defined?(@attributes)
if name = self.class.symbol_column_to_string(name.to_sym)
return _has_attribute?(name)
end
end
true
end
# Returns +true+ if the given attribute is in the attributes hash, otherwise +false+.
#
# class Person < ActiveRecord::Base
# alias_attribute :new_name, :name
# end
#
# person = Person.new
# person.has_attribute?(:name) # => true
# person.has_attribute?(:new_name) # => true
# person.has_attribute?('age') # => true
# person.has_attribute?(:nothing) # => false
def has_attribute?(attr_name)
attr_name = attr_name.to_s
attr_name = self.class.attribute_aliases[attr_name] || attr_name
@attributes.key?(attr_name)
end
def _has_attribute?(attr_name) # :nodoc:
@attributes.key?(attr_name)
end
# Returns an array of names for the attributes available on this object.
#
# class Person < ActiveRecord::Base
# end
#
# person = Person.new
# person.attribute_names
# # => ["id", "created_at", "updated_at", "name", "age"]
def attribute_names
@attributes.keys
end
# Returns a hash of all the attributes with their names as keys and the values of the attributes as values.
#
# class Person < ActiveRecord::Base
# end
#
# person = Person.create(name: 'Francesco', age: 22)
# person.attributes
# # => {"id"=>3, "created_at"=>Sun, 21 Oct 2012 04:53:04, "updated_at"=>Sun, 21 Oct 2012 04:53:04, "name"=>"Francesco", "age"=>22}
def attributes
@attributes.to_hash
end
# Returns an #inspect-like string for the value of the
# attribute +attr_name+. String attributes are truncated up to 50
# characters. Other attributes return the value of #inspect
# without modification.
#
# person = Person.create!(name: 'David Heinemeier Hansson ' * 3)
#
# person.attribute_for_inspect(:name)
# # => "\"David Heinemeier Hansson David Heinemeier Hansson ...\""
#
# person.attribute_for_inspect(:created_at)
# # => "\"2012-10-22 00:15:07.000000000 +0000\""
#
# person.attribute_for_inspect(:tag_ids)
# # => "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]"
def attribute_for_inspect(attr_name)
attr_name = attr_name.to_s
attr_name = self.class.attribute_aliases[attr_name] || attr_name
value = _read_attribute(attr_name)
format_for_inspect(attr_name, value)
end
# Returns +true+ if the specified +attribute+ has been set by the user or by a
# database load and is neither +nil+ nor empty? (the latter only applies
# to objects that respond to empty?, most notably Strings). Otherwise, +false+.
# Note that it always returns +true+ with boolean attributes.
#
# class Task < ActiveRecord::Base
# end
#
# task = Task.new(title: '', is_done: false)
# task.attribute_present?(:title) # => false
# task.attribute_present?(:is_done) # => true
# task.title = 'Buy milk'
# task.is_done = true
# task.attribute_present?(:title) # => true
# task.attribute_present?(:is_done) # => true
def attribute_present?(attr_name)
attr_name = attr_name.to_s
attr_name = self.class.attribute_aliases[attr_name] || attr_name
value = _read_attribute(attr_name)
!value.nil? && !(value.respond_to?(:empty?) && value.empty?)
end
# Returns the value of the attribute identified by +attr_name+ after it has
# been type cast. (For information about specific type casting behavior, see
# the types under ActiveModel::Type.)
#
# class Person < ActiveRecord::Base
# belongs_to :organization
# end
#
# person = Person.new(name: "Francesco", date_of_birth: "2004-12-12")
# person[:name] # => "Francesco"
# person[:date_of_birth] # => Date.new(2004, 12, 12)
# person[:organization_id] # => nil
#
# Raises ActiveModel::MissingAttributeError if the attribute is missing.
# Note, however, that the +id+ attribute will never be considered missing.
#
# person = Person.select(:name).first
# person[:name] # => "Francesco"
# person[:date_of_birth] # => ActiveModel::MissingAttributeError: missing attribute 'date_of_birth' for Person
# person[:organization_id] # => ActiveModel::MissingAttributeError: missing attribute 'organization_id' for Person
# person[:id] # => nil
def [](attr_name)
read_attribute(attr_name) { |n| missing_attribute(n, caller) }
end
# Updates the attribute identified by +attr_name+ using the specified
# +value+. The attribute value will be type cast upon being read.
#
# class Person < ActiveRecord::Base
# end
#
# person = Person.new
# person[:date_of_birth] = "2004-12-12"
# person[:date_of_birth] # => Date.new(2004, 12, 12)
def []=(attr_name, value)
write_attribute(attr_name, value)
end
# Returns the name of all database fields which have been read from this
# model. This can be useful in development mode to determine which fields
# need to be selected. For performance critical pages, selecting only the
# required fields can be an easy performance win (assuming you aren't using
# all of the fields on the model).
#
# For example:
#
# class PostsController < ActionController::Base
# after_action :print_accessed_fields, only: :index
#
# def index
# @posts = Post.all
# end
#
# private
# def print_accessed_fields
# p @posts.first.accessed_fields
# end
# end
#
# Which allows you to quickly change your code to:
#
# class PostsController < ActionController::Base
# def index
# @posts = Post.select(:id, :title, :author_id, :updated_at)
# end
# end
def accessed_fields
@attributes.accessed
end
private
def respond_to_missing?(name, include_private = false)
if self.class.define_attribute_methods
# Some methods weren't defined yet.
return true if self.class.method_defined?(name)
return true if include_private && self.class.private_method_defined?(name)
end
super
end
def method_missing(name, ...)
unless self.class.attribute_methods_generated?
if self.class.method_defined?(name)
# The method is explicitly defined in the model, but calls a generated
# method with super. So we must resume the call chain at the right setp.
last_method = method(name)
last_method = last_method.super_method while last_method.super_method
self.class.define_attribute_methods
if last_method.super_method
return last_method.super_method.call(...)
end
elsif self.class.define_attribute_methods | self.class.generate_alias_attributes
# Some attribute methods weren't generated yet, we retry the call
return public_send(name, ...)
end
end
super
end
def attribute_method?(attr_name)
# We check defined? because Syck calls respond_to? before actually calling initialize.
defined?(@attributes) && @attributes.key?(attr_name)
end
def attributes_with_values(attribute_names)
attribute_names.index_with { |name| @attributes[name] }
end
# Filters the primary keys, readonly attributes and virtual columns from the attribute names.
def attributes_for_update(attribute_names)
attribute_names &= self.class.column_names
attribute_names.delete_if do |name|
self.class.readonly_attribute?(name) ||
self.class.counter_cache_column?(name) ||
column_for_attribute(name).virtual?
end
end
# Filters out the virtual columns and also primary keys, from the attribute names, when the primary
# key is to be generated (e.g. the id attribute has no value).
def attributes_for_create(attribute_names)
attribute_names &= self.class.column_names
attribute_names.delete_if do |name|
(pk_attribute?(name) && id.nil?) ||
column_for_attribute(name).virtual?
end
end
def format_for_inspect(name, value)
if value.nil?
value.inspect
else
inspected_value = if value.is_a?(String) && value.length > 50
"#{value[0, 50]}...".inspect
elsif value.is_a?(Date) || value.is_a?(Time)
%("#{value.to_fs(:inspect)}")
else
value.inspect
end
inspection_filter.filter_param(name, inspected_value)
end
end
def pk_attribute?(name)
name == @primary_key
end
end
end