diff options
Diffstat (limited to 'activemodel/lib/active_model/attribute_mutation_tracker.rb')
-rw-r--r-- | activemodel/lib/active_model/attribute_mutation_tracker.rb | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/attribute_mutation_tracker.rb b/activemodel/lib/active_model/attribute_mutation_tracker.rb new file mode 100644 index 0000000000..9072460124 --- /dev/null +++ b/activemodel/lib/active_model/attribute_mutation_tracker.rb @@ -0,0 +1,114 @@ +# frozen_string_literal: true + +module ActiveModel + class AttributeMutationTracker # :nodoc: + OPTION_NOT_GIVEN = Object.new + + def initialize(attributes) + @attributes = attributes + @forced_changes = Set.new + end + + def changed_values + attr_names.each_with_object({}.with_indifferent_access) do |attr_name, result| + if changed?(attr_name) + result[attr_name] = attributes[attr_name].original_value + end + end + end + + def changes + attr_names.each_with_object({}.with_indifferent_access) do |attr_name, result| + change = change_to_attribute(attr_name) + if change + result[attr_name] = change + end + end + end + + def change_to_attribute(attr_name) + attr_name = attr_name.to_s + if changed?(attr_name) + [attributes[attr_name].original_value, attributes.fetch_value(attr_name)] + end + end + + def any_changes? + attr_names.any? { |attr| changed?(attr) } + end + + def changed?(attr_name, from: OPTION_NOT_GIVEN, to: OPTION_NOT_GIVEN) + attr_name = attr_name.to_s + forced_changes.include?(attr_name) || + attributes[attr_name].changed? && + (OPTION_NOT_GIVEN == from || attributes[attr_name].original_value == from) && + (OPTION_NOT_GIVEN == to || attributes[attr_name].value == to) + end + + def changed_in_place?(attr_name) + attributes[attr_name.to_s].changed_in_place? + end + + def forget_change(attr_name) + attr_name = attr_name.to_s + attributes[attr_name] = attributes[attr_name].forgetting_assignment + forced_changes.delete(attr_name) + end + + def original_value(attr_name) + attributes[attr_name.to_s].original_value + end + + def force_change(attr_name) + forced_changes << attr_name.to_s + end + + # TODO Change this to private once we've dropped Ruby 2.2 support. + # Workaround for Ruby 2.2 "private attribute?" warning. + protected + + attr_reader :attributes, :forced_changes + + private + + def attr_names + attributes.keys + end + end + + class NullMutationTracker # :nodoc: + include Singleton + + def changed_values(*) + {} + end + + def changes(*) + {} + end + + def change_to_attribute(attr_name) + end + + def any_changes?(*) + false + end + + def changed?(*) + false + end + + def changed_in_place?(*) + false + end + + def forget_change(*) + end + + def original_value(*) + end + + def force_change(*) + end + end +end |