295 lines
9.2 KiB
Ruby
295 lines
9.2 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
require "active_model/attribute_mutation_tracker"
|
|
|
|
module ActiveModel
|
|
# == Active \Model \Dirty
|
|
#
|
|
# Provides a way to track changes in your object in the same way as
|
|
# Active Record does.
|
|
#
|
|
# The requirements for implementing ActiveModel::Dirty are:
|
|
#
|
|
# * <tt>include ActiveModel::Dirty</tt> in your object.
|
|
# * Call <tt>define_attribute_methods</tt> passing each method you want to
|
|
# track.
|
|
# * Call <tt>[attr_name]_will_change!</tt> before each change to the tracked
|
|
# attribute.
|
|
# * Call <tt>changes_applied</tt> after the changes are persisted.
|
|
# * Call <tt>clear_changes_information</tt> when you want to reset the changes
|
|
# information.
|
|
# * Call <tt>restore_attributes</tt> when you want to restore previous data.
|
|
#
|
|
# A minimal implementation could be:
|
|
#
|
|
# class Person
|
|
# include ActiveModel::Dirty
|
|
#
|
|
# define_attribute_methods :name
|
|
#
|
|
# def initialize
|
|
# @name = nil
|
|
# end
|
|
#
|
|
# def name
|
|
# @name
|
|
# end
|
|
#
|
|
# def name=(val)
|
|
# name_will_change! unless val == @name
|
|
# @name = val
|
|
# end
|
|
#
|
|
# def save
|
|
# # do persistence work
|
|
#
|
|
# changes_applied
|
|
# end
|
|
#
|
|
# def reload!
|
|
# # get the values from the persistence layer
|
|
#
|
|
# clear_changes_information
|
|
# end
|
|
#
|
|
# def rollback!
|
|
# restore_attributes
|
|
# end
|
|
# end
|
|
#
|
|
# A newly instantiated +Person+ object is unchanged:
|
|
#
|
|
# person = Person.new
|
|
# person.changed? # => false
|
|
#
|
|
# Change the name:
|
|
#
|
|
# person.name = 'Bob'
|
|
# person.changed? # => true
|
|
# person.name_changed? # => true
|
|
# person.name_changed?(from: nil, to: "Bob") # => true
|
|
# person.name_was # => nil
|
|
# person.name_change # => [nil, "Bob"]
|
|
# person.name = 'Bill'
|
|
# person.name_change # => [nil, "Bill"]
|
|
#
|
|
# Save the changes:
|
|
#
|
|
# person.save
|
|
# person.changed? # => false
|
|
# person.name_changed? # => false
|
|
#
|
|
# Reset the changes:
|
|
#
|
|
# person.previous_changes # => {"name" => [nil, "Bill"]}
|
|
# person.name_previously_changed? # => true
|
|
# person.name_previously_changed?(from: nil, to: "Bill") # => true
|
|
# person.name_previous_change # => [nil, "Bill"]
|
|
# person.name_previously_was # => nil
|
|
# person.reload!
|
|
# person.previous_changes # => {}
|
|
#
|
|
# Rollback the changes:
|
|
#
|
|
# person.name = "Uncle Bob"
|
|
# person.rollback!
|
|
# person.name # => "Bill"
|
|
# person.name_changed? # => false
|
|
#
|
|
# Assigning the same value leaves the attribute unchanged:
|
|
#
|
|
# person.name = 'Bill'
|
|
# person.name_changed? # => false
|
|
# person.name_change # => nil
|
|
#
|
|
# Which attributes have changed?
|
|
#
|
|
# person.name = 'Bob'
|
|
# person.changed # => ["name"]
|
|
# person.changes # => {"name" => ["Bill", "Bob"]}
|
|
#
|
|
# If an attribute is modified in-place then make use of
|
|
# <tt>[attribute_name]_will_change!</tt> to mark that the attribute is changing.
|
|
# Otherwise \Active \Model can't track changes to in-place attributes. Note
|
|
# that Active Record can detect in-place modifications automatically. You do
|
|
# not need to call <tt>[attribute_name]_will_change!</tt> on Active Record models.
|
|
#
|
|
# person.name_will_change!
|
|
# person.name_change # => ["Bill", "Bill"]
|
|
# person.name << 'y'
|
|
# person.name_change # => ["Bill", "Billy"]
|
|
module Dirty
|
|
extend ActiveSupport::Concern
|
|
include ActiveModel::AttributeMethods
|
|
|
|
included do
|
|
attribute_method_suffix "_previously_changed?", "_changed?", parameters: "**options"
|
|
attribute_method_suffix "_change", "_will_change!", "_was", parameters: false
|
|
attribute_method_suffix "_previous_change", "_previously_was", parameters: false
|
|
attribute_method_affix prefix: "restore_", suffix: "!", parameters: false
|
|
attribute_method_affix prefix: "clear_", suffix: "_change", parameters: false
|
|
end
|
|
|
|
def initialize_dup(other) # :nodoc:
|
|
super
|
|
if self.class.respond_to?(:_default_attributes)
|
|
@attributes = self.class._default_attributes.map do |attr|
|
|
attr.with_value_from_user(@attributes.fetch_value(attr.name))
|
|
end
|
|
end
|
|
@mutations_from_database = nil
|
|
end
|
|
|
|
def as_json(options = {}) # :nodoc:
|
|
options[:except] = [*options[:except], "mutations_from_database", "mutations_before_last_save"]
|
|
super(options)
|
|
end
|
|
|
|
# Clears dirty data and moves +changes+ to +previous_changes+ and
|
|
# +mutations_from_database+ to +mutations_before_last_save+ respectively.
|
|
def changes_applied
|
|
unless defined?(@attributes)
|
|
mutations_from_database.finalize_changes
|
|
end
|
|
@mutations_before_last_save = mutations_from_database
|
|
forget_attribute_assignments
|
|
@mutations_from_database = nil
|
|
end
|
|
|
|
# Returns +true+ if any of the attributes has unsaved changes, +false+ otherwise.
|
|
#
|
|
# person.changed? # => false
|
|
# person.name = 'bob'
|
|
# person.changed? # => true
|
|
def changed?
|
|
mutations_from_database.any_changes?
|
|
end
|
|
|
|
# Returns an array with the name of the attributes with unsaved changes.
|
|
#
|
|
# person.changed # => []
|
|
# person.name = 'bob'
|
|
# person.changed # => ["name"]
|
|
def changed
|
|
mutations_from_database.changed_attribute_names
|
|
end
|
|
|
|
# Dispatch target for <tt>*_changed?</tt> attribute methods.
|
|
def attribute_changed?(attr_name, **options) # :nodoc:
|
|
mutations_from_database.changed?(attr_name.to_s, **options)
|
|
end
|
|
|
|
# Dispatch target for <tt>*_was</tt> attribute methods.
|
|
def attribute_was(attr_name) # :nodoc:
|
|
mutations_from_database.original_value(attr_name.to_s)
|
|
end
|
|
|
|
# Dispatch target for <tt>*_previously_changed?</tt> attribute methods.
|
|
def attribute_previously_changed?(attr_name, **options) # :nodoc:
|
|
mutations_before_last_save.changed?(attr_name.to_s, **options)
|
|
end
|
|
|
|
# Dispatch target for <tt>*_previously_was</tt> attribute methods.
|
|
def attribute_previously_was(attr_name) # :nodoc:
|
|
mutations_before_last_save.original_value(attr_name.to_s)
|
|
end
|
|
|
|
# Restore all previous data of the provided attributes.
|
|
def restore_attributes(attr_names = changed)
|
|
attr_names.each { |attr_name| restore_attribute!(attr_name) }
|
|
end
|
|
|
|
# Clears all dirty data: current changes and previous changes.
|
|
def clear_changes_information
|
|
@mutations_before_last_save = nil
|
|
forget_attribute_assignments
|
|
@mutations_from_database = nil
|
|
end
|
|
|
|
def clear_attribute_changes(attr_names)
|
|
attr_names.each do |attr_name|
|
|
clear_attribute_change(attr_name)
|
|
end
|
|
end
|
|
|
|
# Returns a hash of the attributes with unsaved changes indicating their original
|
|
# values like <tt>attr => original value</tt>.
|
|
#
|
|
# person.name # => "bob"
|
|
# person.name = 'robert'
|
|
# person.changed_attributes # => {"name" => "bob"}
|
|
def changed_attributes
|
|
mutations_from_database.changed_values
|
|
end
|
|
|
|
# Returns a hash of changed attributes indicating their original
|
|
# and new values like <tt>attr => [original value, new value]</tt>.
|
|
#
|
|
# person.changes # => {}
|
|
# person.name = 'bob'
|
|
# person.changes # => { "name" => ["bill", "bob"] }
|
|
def changes
|
|
mutations_from_database.changes
|
|
end
|
|
|
|
# Returns a hash of attributes that were changed before the model was saved.
|
|
#
|
|
# person.name # => "bob"
|
|
# person.name = 'robert'
|
|
# person.save
|
|
# person.previous_changes # => {"name" => ["bob", "robert"]}
|
|
def previous_changes
|
|
mutations_before_last_save.changes
|
|
end
|
|
|
|
def attribute_changed_in_place?(attr_name) # :nodoc:
|
|
mutations_from_database.changed_in_place?(attr_name.to_s)
|
|
end
|
|
|
|
private
|
|
def clear_attribute_change(attr_name)
|
|
mutations_from_database.forget_change(attr_name.to_s)
|
|
end
|
|
|
|
def mutations_from_database
|
|
@mutations_from_database ||= if defined?(@attributes)
|
|
ActiveModel::AttributeMutationTracker.new(@attributes)
|
|
else
|
|
ActiveModel::ForcedMutationTracker.new(self)
|
|
end
|
|
end
|
|
|
|
def forget_attribute_assignments
|
|
@attributes = @attributes.map(&:forgetting_assignment) if defined?(@attributes)
|
|
end
|
|
|
|
def mutations_before_last_save
|
|
@mutations_before_last_save ||= ActiveModel::NullMutationTracker.instance
|
|
end
|
|
|
|
# Dispatch target for <tt>*_change</tt> attribute methods.
|
|
def attribute_change(attr_name)
|
|
mutations_from_database.change_to_attribute(attr_name.to_s)
|
|
end
|
|
|
|
# Dispatch target for <tt>*_previous_change</tt> attribute methods.
|
|
def attribute_previous_change(attr_name)
|
|
mutations_before_last_save.change_to_attribute(attr_name.to_s)
|
|
end
|
|
|
|
# Dispatch target for <tt>*_will_change!</tt> attribute methods.
|
|
def attribute_will_change!(attr_name)
|
|
mutations_from_database.force_change(attr_name.to_s)
|
|
end
|
|
|
|
# Dispatch target for <tt>restore_*!</tt> attribute methods.
|
|
def restore_attribute!(attr_name)
|
|
attr_name = attr_name.to_s
|
|
if attribute_changed?(attr_name)
|
|
__send__("#{attr_name}=", attribute_was(attr_name))
|
|
clear_attribute_change(attr_name)
|
|
end
|
|
end
|
|
end
|
|
end
|