module ActiveModel::AttributeMethods::ClassMethods
def alias_attribute(new_name, old_name)
person.name_short? # => true
person.nickname # => "Bob"
person.name # => "Bob"
person.name = 'Bob'
person = Person.new
end
end
send(attr).length < 5
def attribute_short?(attr)
private
alias_attribute :nickname, :name
define_attribute_methods :name
attribute_method_suffix '_short?'
attr_accessor :name
include ActiveModel::AttributeMethods
class Person
Allows you to make aliases for attributes.
def alias_attribute(new_name, old_name) self.attribute_aliases = attribute_aliases.merge(new_name.to_s => old_name.to_s) ActiveSupport::CodeGenerator.batch(self, __FILE__, __LINE__) do |code_generator| attribute_method_matchers.each do |matcher| method_name = matcher.method_name(new_name).to_s target_name = matcher.method_name(old_name).to_s parameters = matcher.parameters mangled_name = target_name unless NAME_COMPILABLE_REGEXP.match?(target_name) mangled_name = "__temp__#{target_name.unpack1("h*")}" end code_generator.define_cached_method(method_name, as: mangled_name, namespace: :alias_attribute) do |batch| body = if CALL_COMPILABLE_REGEXP.match?(target_name) "self.#{target_name}(#{parameters || ''})" else call_args = [":'#{target_name}'"] call_args << parameters if parameters "send(#{call_args.join(", ")})" end modifier = matcher.parameters == FORWARD_PARAMETERS ? "ruby2_keywords " : "" batch << "#{modifier}def #{mangled_name}(#{parameters || ''})" << body << "end" end end end end
def attribute_alias(name)
def attribute_alias(name) attribute_aliases[name.to_s] end
def attribute_alias?(new_name)
def attribute_alias?(new_name) attribute_aliases.key? new_name.to_s end
def attribute_method_affix(*affixes)
person.reset_name_to_default!
person.name # => 'Gem'
person = Person.new
end
end
send("#{attr}=", 'Default Name')
def reset_attribute_to_default!(attr)
private
define_attribute_methods :name
attribute_method_affix prefix: 'reset_', suffix: '_to_default!'
attr_accessor :name
include ActiveModel::AttributeMethods
class Person
accept at least the +attr+ argument.
An #{prefix}attribute#{suffix} instance method must exist and
#{prefix}attribute#{suffix}(#{attr}, *args, &block)
to
#{prefix}#{attr}#{suffix}(*args, &block)
the method.
and suffix. Uses +method_missing+ and respond_to? to rewrite
Declares a method available for all attributes with the given prefix
def attribute_method_affix(*affixes) self.attribute_method_matchers += affixes.map! { |affix| AttributeMethodMatcher.new(**affix) } undefine_attribute_methods end
def attribute_method_matchers_cache
significantly (in our case our test suite finishes 10% faster with
used to alleviate the GC, which ultimately also speeds up the app
match result is always the same given a +method_name+, this cache is
object creations. Most of the time it returns a +nil+ match. As the
array doing regular expression matches, which results in a lot of
+matched_attribute_method+. The latter method iterates through an
invoked often in a typical rails, both of which invoke the method
The methods +method_missing+ and +respond_to?+ of this module are
def attribute_method_matchers_cache @attribute_method_matchers_cache ||= Concurrent::Map.new(initial_capacity: 4) end
def attribute_method_matchers_matching(method_name)
def attribute_method_matchers_matching(method_name) attribute_method_matchers_cache.compute_if_absent(method_name) do attribute_method_matchers.filter_map { |matcher| matcher.match(method_name) } end end
def attribute_method_prefix(*prefixes, parameters: nil)
person.clear_name
person.name # => "Bob"
person.name = 'Bob'
person = Person.new
end
end
send("#{attr}=", nil)
def clear_attribute(attr)
private
define_attribute_methods :name
attribute_method_prefix 'clear_'
attr_accessor :name
include ActiveModel::AttributeMethods
class Person
at least the +attr+ argument.
An instance method #{prefix}attribute must exist and accept
#{prefix}attribute(#{attr}, *args, &block)
to
#{prefix}#{attr}(*args, &block)
Uses +method_missing+ and respond_to? to rewrite the method.
Declares a method available for all attributes with the given prefix.
def attribute_method_prefix(*prefixes, parameters: nil) self.attribute_method_matchers += prefixes.map! { |prefix| AttributeMethodMatcher.new(prefix: prefix, parameters: parameters) } undefine_attribute_methods end
def attribute_method_suffix(*suffixes, parameters: nil)
person.name # => "Bob"
person.name = 'Bob'
person = Person.new
end
end
send(attr).length < 5
def attribute_short?(attr)
private
define_attribute_methods :name
attribute_method_suffix '_short?'
attr_accessor :name
include ActiveModel::AttributeMethods
class Person
least the +attr+ argument.
An attribute#{suffix} instance method must exist and accept at
attribute#{suffix}(#{attr}, *args, &block)
to
#{attr}#{suffix}(*args, &block)
Uses +method_missing+ and respond_to? to rewrite the method.
Declares a method available for all attributes with the given suffix.
def attribute_method_suffix(*suffixes, parameters: nil) self.attribute_method_matchers += suffixes.map! { |suffix| AttributeMethodMatcher.new(suffix: suffix, parameters: parameters) } undefine_attribute_methods end
def define_attribute_method(attr_name, _owner: generated_attribute_methods)
person.name # => "Bob"
person.name = 'Bob'
person = Person.new
end
end
send(attr).length < 5
def attribute_short?(attr)
private
define_attribute_method :name
# attribute_method_affix declarations.
# attribute_method_prefix, attribute_method_suffix or
# Call to define_attribute_method must appear after the
attribute_method_suffix '_short?'
attr_accessor :name
include ActiveModel::AttributeMethods
class Person
method, or they will not hook in.
+define_attribute_method+ after you define any prefix, suffix or affix
To use, pass an attribute name (as string or symbol). Be sure to declare
ActiveModel::AttributeMethods.
Declares an attribute that should be prefixed and suffixed by
def define_attribute_method(attr_name, _owner: generated_attribute_methods) ActiveSupport::CodeGenerator.batch(_owner, __FILE__, __LINE__) do |owner| attribute_method_matchers.each do |matcher| method_name = matcher.method_name(attr_name) unless instance_method_already_implemented?(method_name) generate_method = "define_method_#{matcher.target}" if respond_to?(generate_method, true) send(generate_method, attr_name.to_s, owner: owner) else define_proxy_call(owner, method_name, matcher.target, matcher.parameters, attr_name.to_s, namespace: :active_model_proxy) end end end attribute_method_matchers_cache.clear end end
def define_attribute_methods(*attr_names)
end
send("#{attr}=", nil)
def clear_attribute(attr)
private
define_attribute_methods :name, :age, :address
# attribute_method_affix declarations.
# attribute_method_prefix, attribute_method_suffix or
# Call to define_attribute_methods must appear after the
attribute_method_prefix 'clear_'
attr_accessor :name, :age, :address
include ActiveModel::AttributeMethods
class Person
methods, or they will not hook in.
+define_attribute_methods+ after you define any prefix, suffix, or affix
To use, pass attribute names (as strings or symbols). Be sure to declare
ActiveModel::AttributeMethods.
Declares the attributes that should be prefixed and suffixed by
def define_attribute_methods(*attr_names) ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |owner| attr_names.flatten.each { |attr_name| define_attribute_method(attr_name, _owner: owner) } end end
def define_proxy_call(code_generator, name, target, parameters, *call_args, namespace:)
using the given `extra` args. This falls back on `send`
Define a method `name` in `mod` that dispatches to `send`
def define_proxy_call(code_generator, name, target, parameters, *call_args, namespace:) mangled_name = name unless NAME_COMPILABLE_REGEXP.match?(name) mangled_name = "__temp__#{name.unpack1("h*")}" end code_generator.define_cached_method(name, as: mangled_name, namespace: :"#{namespace}_#{target}") do |batch| call_args.map!(&:inspect) call_args << parameters if parameters body = if CALL_COMPILABLE_REGEXP.match?(target) "self.#{target}(#{call_args.join(", ")})" else call_args.unshift(":'#{target}'") "send(#{call_args.join(", ")})" end modifier = parameters == FORWARD_PARAMETERS ? "ruby2_keywords " : "" batch << "#{modifier}def #{mangled_name}(#{parameters || ''})" << body << "end" end end
def generated_attribute_methods
def generated_attribute_methods @generated_attribute_methods ||= Module.new.tap { |mod| include mod } end
def instance_method_already_implemented?(method_name)
def instance_method_already_implemented?(method_name) generated_attribute_methods.method_defined?(method_name) end
def undefine_attribute_methods
Person.undefine_attribute_methods
person.name_short? # => true
person.name = 'Bob'
person = Person.new
end
end
send(attr).length < 5
def attribute_short?(attr)
private
define_attribute_method :name
attribute_method_suffix '_short?'
attr_accessor :name
include ActiveModel::AttributeMethods
class Person
Removes all the previously dynamically defined methods from the class.
def undefine_attribute_methods generated_attribute_methods.module_eval do undef_method(*instance_methods) end attribute_method_matchers_cache.clear end