# frozen_string_literal: true module PaperTrail module Events # We refer to times in the lifecycle of a record as "events". There are # three events: # # - create # - `after_create` we call `RecordTrail#record_create` # - update # - `after_update` we call `RecordTrail#record_update` # - `after_touch` we call `RecordTrail#record_update` # - `RecordTrail#save_with_version` calls `RecordTrail#record_update` # - `RecordTrail#update_columns` is also referred to as an update, though # it uses `RecordTrail#record_update_columns` rather than # `RecordTrail#record_update` # - destroy # - `before_destroy` or `after_destroy` we call `RecordTrail#record_destroy` # # The value inserted into the `event` column of the versions table can also # be overridden by the user, with `paper_trail_event`. # # @api private class Base # @api private def initialize(record, in_after_callback) @record = record @in_after_callback = in_after_callback end # Determines whether it is appropriate to generate a new version # instance. A timestamp-only update (e.g. only `updated_at` changed) is # considered notable unless an ignored attribute was also changed. # # @api private def changed_notably? if ignored_attr_has_changed? timestamps = @record.send(:timestamp_attributes_for_update_in_model).map(&:to_s) (notably_changed - timestamps).any? else notably_changed.any? end end private # Rails 5.1 changed the API of `ActiveRecord::Dirty`. See # https://github.com/paper-trail-gem/paper_trail/pull/899 # # @api private def attribute_changed_in_latest_version?(attr_name) if @in_after_callback @record.saved_change_to_attribute?(attr_name.to_s) else @record.attribute_changed?(attr_name.to_s) end end # @api private def nonskipped_attributes_before_change(is_touch) record_attributes = @record.attributes.except(*@record.paper_trail_options[:skip]) record_attributes.each_key do |k| if @record.class.column_names.include?(k) record_attributes[k] = attribute_in_previous_version(k, is_touch) end end end # Rails 5.1 changed the API of `ActiveRecord::Dirty`. See # https://github.com/paper-trail-gem/paper_trail/pull/899 # # Event can be any of the three (create, update, destroy). # # @api private def attribute_in_previous_version(attr_name, is_touch) if @in_after_callback && !is_touch # For most events, we want the original value of the attribute, before # the last save. @record.attribute_before_last_save(attr_name.to_s) else # We are either performing a `record_destroy` or a # `record_update(is_touch: true)`. @record.attribute_in_database(attr_name.to_s) end end # @api private def calculated_ignored_array ignore = @record.paper_trail_options[:ignore].dup # Remove Hash arguments and then evaluate whether the attributes (the # keys of the hash) should also get pushed into the collection. ignore.delete_if do |obj| obj.is_a?(Hash) && obj.each { |attr, condition| ignore << attr if condition.respond_to?(:call) && condition.call(@record) } end end # @api private def changed_and_not_ignored skip = @record.paper_trail_options[:skip] (changed_in_latest_version - calculated_ignored_array) - skip end # @api private def changed_in_latest_version # Memoized to reduce memory usage @changed_in_latest_version ||= changes_in_latest_version.keys end # Memoized to reduce memory usage # # @api private def changes_in_latest_version @changes_in_latest_version ||= load_changes_in_latest_version end # An attributed is "ignored" if it is listed in the `:ignore` option # and/or the `:skip` option. Returns true if an ignored attribute has # changed. # # @api private def ignored_attr_has_changed? ignored = calculated_ignored_array + @record.paper_trail_options[:skip] ignored.any? && (changed_in_latest_version & ignored).any? end # Rails 5.1 changed the API of `ActiveRecord::Dirty`. See # https://github.com/paper-trail-gem/paper_trail/pull/899 # # @api private def load_changes_in_latest_version if @in_after_callback @record.saved_changes else @record.changes end end # PT 10 has a new optional column, `item_subtype` # # @api private def merge_item_subtype_into(data) if @record.class.paper_trail.version_class.columns_hash.key?("item_subtype") data.merge!(item_subtype: @record.class.name) end end # Updates `data` from the model's `meta` option and from `controller_info`. # Metadata is always recorded; that means all three events (create, update, # destroy) and `update_columns`. # # @api private def merge_metadata_into(data) merge_metadata_from_model_into(data) merge_metadata_from_controller_into(data) end # Updates `data` from `controller_info`. # # @api private def merge_metadata_from_controller_into(data) data.merge(PaperTrail.request.controller_info || {}) end # Updates `data` from the model's `meta` option. # # @api private def merge_metadata_from_model_into(data) @record.paper_trail_options[:meta].each do |k, v| data[k] = model_metadatum(v, data[:event]) end end # Given a `value` from the model's `meta` option, returns an object to be # persisted. The `value` can be a simple scalar value, but it can also # be a symbol that names a model method, or even a Proc. # # @api private def model_metadatum(value, event) if value.respond_to?(:call) value.call(@record) elsif value.is_a?(Symbol) && @record.respond_to?(value, true) # If it is an attribute that is changing in an existing object, # be sure to grab the current version. if event != "create" && @record.has_attribute?(value) && attribute_changed_in_latest_version?(value) attribute_in_previous_version(value, false) else @record.send(value) end else value end end # @api private def notable_changes changes_in_latest_version.delete_if { |k, _v| !notably_changed.include?(k) } end # @api private def notably_changed # Memoized to reduce memory usage @notably_changed ||= begin only = @record.paper_trail_options[:only].dup # Remove Hash arguments and then evaluate whether the attributes (the # keys of the hash) should also get pushed into the collection. only.delete_if do |obj| obj.is_a?(Hash) && obj.each { |attr, condition| only << attr if condition.respond_to?(:call) && condition.call(@record) } end only.empty? ? changed_and_not_ignored : (changed_and_not_ignored & only) end end # Returns hash of attributes (with appropriate attributes serialized), # omitting attributes to be skipped. # # @api private def object_attrs_for_paper_trail(is_touch) attrs = nonskipped_attributes_before_change(is_touch) AttributeSerializers::ObjectAttribute.new(@record.class).serialize(attrs) attrs end # @api private def prepare_object_changes(changes) changes = serialize_object_changes(changes) recordable_object_changes(changes) end # Returns an object which can be assigned to the `object_changes` # attribute of a nascent version record. If the `object_changes` column is # a postgres `json` column, then a hash can be used in the assignment, # otherwise the column is a `text` column, and we must perform the # serialization here, using `PaperTrail.serializer`. # # @api private # @param changes HashWithIndifferentAccess def recordable_object_changes(changes) if PaperTrail.config.object_changes_adapter.respond_to?(:diff) # We'd like to avoid the `to_hash` here, because it increases memory # usage, but that would be a breaking change because # `object_changes_adapter` expects a plain `Hash`, not a # `HashWithIndifferentAccess`. changes = PaperTrail.config.object_changes_adapter.diff(changes.to_hash) end if @record.class.paper_trail.version_class.object_changes_col_is_json? changes else PaperTrail.serializer.dump(changes) end end # Returns a boolean indicating whether to store serialized version diffs # in the `object_changes` column of the version record. # # @api private def record_object_changes? @record.class.paper_trail.version_class.column_names.include?("object_changes") end # Returns a boolean indicating whether to store the original object during save. # # @api private def record_object? @record.class.paper_trail.version_class.column_names.include?("object") end # Returns an object which can be assigned to the `object` attribute of a # nascent version record. If the `object` column is a postgres `json` # column, then a hash can be used in the assignment, otherwise the column # is a `text` column, and we must perform the serialization here, using # `PaperTrail.serializer`. # # @api private def recordable_object(is_touch) if @record.class.paper_trail.version_class.object_col_is_json? object_attrs_for_paper_trail(is_touch) else PaperTrail.serializer.dump(object_attrs_for_paper_trail(is_touch)) end end # @api private def serialize_object_changes(changes) AttributeSerializers::ObjectChangesAttribute. new(@record.class). serialize(changes) # We'd like to convert this `HashWithIndifferentAccess` to a plain # `Hash`, but we don't, to save memory. changes end end end end