# module ActiveRecord::AttributeMethods::Dirty

### Public Instance Methods

attribute_before_last_save(attr_name) click to toggle source

Returns the original value of an attribute before the last save. Behaves similarly to `attribute_was`. This method is useful in after callbacks to get the original value of an attribute before the save that just occurred

    # File lib/active_record/attribute_methods/dirty.rb, line 164
    def attribute_before_last_save(attr_name)
      mutations_before_last_save.original_value(attr_name)
    end

attribute_change(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 218
    def attribute_change(*)
      emit_warning_if_needed("attribute_change", "saved_change_to_attribute")
      super
    end

attribute_change_to_be_saved(attr_name) click to toggle source

Alias for `attribute_change`

    # File lib/active_record/attribute_methods/dirty.rb, line 184
    def attribute_change_to_be_saved(attr_name)
      mutations_from_database.change_to_attribute(attr_name)
    end

attribute_changed?(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 223
    def attribute_changed?(*)
      emit_warning_if_needed("attribute_changed?", "saved_change_to_attribute?")
      super
    end

attribute_in_database(attr_name) click to toggle source

Alias for `attribute_was`

    # File lib/active_record/attribute_methods/dirty.rb, line 189
    def attribute_in_database(attr_name)
      mutations_from_database.original_value(attr_name)
    end

attribute_was(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 213
    def attribute_was(*)
      emit_warning_if_needed("attribute_was", "attribute_before_last_save")
      super
    end

attributes_in_database() click to toggle source

Alias for `changed_attributes`

    # File lib/active_record/attribute_methods/dirty.rb, line 209
    def attributes_in_database
      changes_to_save.transform_values(&:first)
    end

changed(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 233
    def changed(*)
      emit_warning_if_needed("changed", "saved_changes.keys")
      super
    end

changed?(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 228
    def changed?(*)
      emit_warning_if_needed("changed?", "saved_changes?")
      super
    end

changed_attribute_names_to_save() click to toggle source

Alias for `changed`

    # File lib/active_record/attribute_methods/dirty.rb, line 204
    def changed_attribute_names_to_save
      changes_to_save.keys
    end

changes_to_save() click to toggle source

Alias for `changes`

    # File lib/active_record/attribute_methods/dirty.rb, line 199
    def changes_to_save
      mutations_from_database.changes
    end

has_changes_to_save?() click to toggle source

Alias for `changed?`

    # File lib/active_record/attribute_methods/dirty.rb, line 194
    def has_changes_to_save?
      mutations_from_database.any_changes?
    end

reload(*) click to toggle source

`reload` the record and clears changed attributes.

Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 48
    def reload(*)
      super.tap do
        @previous_mutation_tracker = nil
        clear_mutation_trackers
        @changed_attributes = ActiveSupport::HashWithIndifferentAccess.new
      end
    end

save(*) click to toggle source

Attempts to `save` the record and clears changed attributes if successful.

Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 33
    def save(*)
      if status = super
        changes_applied
      end
      status
    end

save!(*) click to toggle source

Attempts to `save!` the record and clears changed attributes if successful.

Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 41
    def save!(*)
      super.tap do
        changes_applied
      end
    end

saved_change_to_attribute(attr_name) click to toggle source

Returns the change to an attribute during the last save. If the attribute was changed, the result will be an array containing the original value and the saved value.

Behaves similarly to `attribute_change`. This method is useful in after callbacks, to see the change in an attribute that just occurred

This method can be invoked as `saved_change_to_name` in instead of `saved_change_to_attribute(“name”)`

    # File lib/active_record/attribute_methods/dirty.rb, line 156
    def saved_change_to_attribute(attr_name)
      mutations_before_last_save.change_to_attribute(attr_name)
    end

saved_change_to_attribute?(attr_name, **options) click to toggle source

Did this attribute change when we last saved? This method can be invoked as `saved_change_to_name?` instead of `saved_change_to_attribute?(“name”)`. Behaves similarly to `attribute_changed?`. This method is useful in after callbacks to determine if the call to save changed a certain attribute.

#### Options¶ ↑

`from` When passed, this method will return false unless the original value is equal to the given option

`to` When passed, this method will return false unless the value was changed to the given value

    # File lib/active_record/attribute_methods/dirty.rb, line 143
    def saved_change_to_attribute?(attr_name, **options)
      mutations_before_last_save.changed?(attr_name, **options)
    end

saved_changes() click to toggle source

Returns a hash containing all the changes that were just saved.

    # File lib/active_record/attribute_methods/dirty.rb, line 174
    def saved_changes
      mutations_before_last_save.changes
    end

saved_changes?() click to toggle source

Did the last call to `save` have any changes to change?

    # File lib/active_record/attribute_methods/dirty.rb, line 169
    def saved_changes?
      mutations_before_last_save.any_changes?
    end

will_save_change_to_attribute?(attr_name, **options) click to toggle source

Alias for `attribute_changed?`

    # File lib/active_record/attribute_methods/dirty.rb, line 179
    def will_save_change_to_attribute?(attr_name, **options)
      mutations_from_database.changed?(attr_name, **options)
    end

### Private Instance Methods

_create_record(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 294
    def _create_record(*)
      partial_writes? ? super(keys_for_partial_write) : super
    end

_update_record(*) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 290
    def _update_record(*)
      partial_writes? ? super(keys_for_partial_write) : super
    end

attribute_will_change!(attr_name) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 275
            def attribute_will_change!(attr_name)
              super
              if self.class.has_attribute?(attr_name)
                mutations_from_database.force_change(attr_name)
              else
                ActiveSupport::Deprecation.warn("              #{attr_name} is not an attribute known to Active Record.
                  This behavior is deprecated and will be removed in the next
                  version of Rails. If you'd like #{attr_name} to be managed
                  by Active Record, add `attribute :#{attr_name} to your class.
    ".squish)
                mutations_from_database.deprecated_force_change(attr_name)
              end
            end

cache_changed_attributes() { || ... } click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 320
    def cache_changed_attributes
      @cached_changed_attributes = changed_attributes
      yield
    ensure
      clear_changed_attributes_cache
    end

changes_include?(attr_name) click to toggle source
Calls superclass method

    # File lib/active_record/attribute_methods/dirty.rb, line 266
    def changes_include?(attr_name)
      super || mutation_tracker.changed?(attr_name)
    end

clear_attribute_change(attr_name) click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 270
    def clear_attribute_change(attr_name)
      mutation_tracker.forget_change(attr_name)
      mutations_from_database.forget_change(attr_name)
    end

clear_changed_attributes_cache() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 327
    def clear_changed_attributes_cache
      remove_instance_variable(:@cached_changed_attributes) if defined?(@cached_changed_attributes)
    end

clear_mutation_trackers() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 306
    def clear_mutation_trackers
      @mutation_tracker = nil
      @mutations_from_database = nil
      @mutations_before_last_save = nil
    end

emit_warning_if_needed(method_name, new_method_name) click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 247
            def emit_warning_if_needed(method_name, new_method_name)
              unless mutation_tracker.equal?(mutations_from_database)
                ActiveSupport::Deprecation.warn("              The behavior of `#{method_name}` inside of after callbacks will
                  be changing in the next version of Rails. The new return value will reflect the
                  behavior of calling the method after `save` returned (e.g. the opposite of what
                  it returns now). To maintain the current behavior, use `#{new_method_name}`
                  instead.
    ".squish)
              end
            end

forget_attribute_assignments() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 302
    def forget_attribute_assignments
      @attributes = @attributes.map(&:forgetting_assignment)
    end

keys_for_partial_write() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 298
    def keys_for_partial_write
      changed_attribute_names_to_save & self.class.column_names
    end

mutation_tracker() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 240
    def mutation_tracker
      unless defined?(@mutation_tracker)
        @mutation_tracker = nil
      end
      @mutation_tracker ||= AttributeMutationTracker.new(@attributes)
    end

mutations_before_last_save() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 316
    def mutations_before_last_save
      @mutations_before_last_save ||= previous_mutation_tracker
    end

mutations_from_database() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 259
    def mutations_from_database
      unless defined?(@mutations_from_database)
        @mutations_from_database = nil
      end
      @mutations_from_database ||= mutation_tracker
    end

previous_mutation_tracker() click to toggle source

    # File lib/active_record/attribute_methods/dirty.rb, line 312
    def previous_mutation_tracker
      @previous_mutation_tracker ||= NullMutationTracker.instance
    end