require 'active_support/core_ext/module/attribute_accessors'
module ActiveRecord
module AttributeMethods
module Dirty # :nodoc:
extend ActiveSupport::Concern
include ActiveModel::Dirty
included do
if self < ::ActiveRecord::Timestamp
raise "You cannot include Dirty after Timestamp"
end
class_attribute :partial_writes, instance_writer: false
self.partial_writes = true
end
# Attempts to +save+ the record and clears changed attributes if successful.
def save(*)
if status = super
changes_applied
end
status
end
# Attempts to <tt>save!</tt> the record and clears changed attributes if successful.
def save!(*)
super.tap do
changes_applied
end
end
# <tt>reload</tt> the record and clears changed attributes.
def reload(*)
super.tap do
reset_changes
end
end
def initialize_dup(other) # :nodoc:
super
init_changed_attributes
end
private
def initialize_internals_callback
super
init_changed_attributes
end
def init_changed_attributes
@changed_attributes = nil
# Intentionally avoid using #column_defaults since overridden defaults (as is done in
# optimistic locking) won't get written unless they get marked as changed
self.class.columns.each do |c|
attr, orig_value = c.name, c.default
changed_attributes[attr] = orig_value if _field_changed?(attr, orig_value, @raw_attributes[attr])
end
end
# Wrap write_attribute to remember original attribute value.
def write_attribute(attr, value)
attr = attr.to_s
save_changed_attribute(attr, value)
super(attr, value)
end
def save_changed_attribute(attr, value)
# The attribute already has an unsaved change.
if attribute_changed?(attr)
old = changed_attributes[attr]
changed_attributes.delete(attr) unless _field_changed?(attr, old, value)
else
old = clone_attribute_value(:read_attribute, attr)
changed_attributes[attr] = old if _field_changed?(attr, old, value)
end
end
def _update_record(*)
partial_writes? ? super(keys_for_partial_write) : super
end
def _create_record(*)
partial_writes? ? super(keys_for_partial_write) : super
end
# Serialized attributes should always be written in case they've been
# changed in place.
def keys_for_partial_write
changed
end
def _field_changed?(attr, old, value)
if column = column_for_attribute(attr)
if column.number? && (changes_from_nil_to_empty_string?(column, old, value) ||
changes_from_zero_to_string?(old, value))
value = nil
else
value = column.type_cast(value)
end
end
old != value
end
def changes_from_nil_to_empty_string?(column, old, value)
# For nullable numeric columns, NULL gets stored in database for blank (i.e. '') values.
# Hence we don't record it as a change if the value changes from nil to ''.
# If an old value of 0 is set to '' we want this to get changed to nil as otherwise it'll
# be typecast back to 0 (''.to_i => 0)
column.null && (old.nil? || old == 0) && value.blank?
end
def changes_from_zero_to_string?(old, value)
# For columns with old 0 and value non-empty string
old == 0 && value.is_a?(String) && value.present? && non_zero?(value)
end
def non_zero?(value)
value !~ /\A0+(\.0+)?\z/
end
end
end
end