Active Record automatically timestamps create and update operations if the
table has fields named created_at/created_on
or
updated_at/updated_on
.
Timestamping can be turned off by setting:
config.active_record.record_timestamps = false
Timestamps are in the local timezone by default but you can use UTC by setting:
config.active_record.default_timezone = :utc
By default, ActiveRecord::Base keeps all the datetime columns time zone aware by executing following code.
config.active_record.time_zone_aware_attributes = true
This feature can easily be turned off by assigning value false
.
If your attributes are time zone aware and you desire to skip time zone conversion to the current Time.zone when reading certain attributes then you can do following:
class Topic < ActiveRecord::Base self.skip_time_zone_conversion_for_attributes = [:written_on] end
# File lib/active_record/timestamp.rb, line 97 def all_timestamp_attributes timestamp_attributes_for_create + timestamp_attributes_for_update end
# File lib/active_record/timestamp.rb, line 85 def all_timestamp_attributes_in_model timestamp_attributes_for_create_in_model + timestamp_attributes_for_update_in_model end
Clear attributes and changed_attributes
# File lib/active_record/timestamp.rb, line 112 def clear_timestamp_attributes all_timestamp_attributes_in_model.each do |attribute_name| self[attribute_name] = nil changed_attributes.delete(attribute_name) end end
# File lib/active_record/timestamp.rb, line 46 def create_record if self.record_timestamps current_time = current_time_from_proper_timezone all_timestamp_attributes.each do |column| if respond_to?(column) && respond_to?("#{column}=") && self.send(column).nil? write_attribute(column.to_s, current_time) end end end super end
# File lib/active_record/timestamp.rb, line 107 def current_time_from_proper_timezone self.class.default_timezone == :utc ? Time.now.utc : Time.now end
# File lib/active_record/timestamp.rb, line 101 def max_updated_column_timestamp if (timestamps = timestamp_attributes_for_update.map { |attr| self[attr] }.compact).present? timestamps.map { |ts| ts.to_time }.max end end
# File lib/active_record/timestamp.rb, line 73 def should_record_timestamps? self.record_timestamps && (!partial_writes? || changed? || (attributes.keys & self.class.serialized_attributes.keys).present?) end
# File lib/active_record/timestamp.rb, line 93 def timestamp_attributes_for_create [:created_at, :created_on] end
# File lib/active_record/timestamp.rb, line 77 def timestamp_attributes_for_create_in_model timestamp_attributes_for_create.select { |c| self.class.column_names.include?(c.to_s) } end
# File lib/active_record/timestamp.rb, line 89 def timestamp_attributes_for_update [:updated_at, :updated_on] end
# File lib/active_record/timestamp.rb, line 81 def timestamp_attributes_for_update_in_model timestamp_attributes_for_update.select { |c| self.class.column_names.include?(c.to_s) } end
# File lib/active_record/timestamp.rb, line 60 def update_record(*args) if should_record_timestamps? current_time = current_time_from_proper_timezone timestamp_attributes_for_update_in_model.each do |column| column = column.to_s next if attribute_changed?(column) write_attribute(column, current_time) end end super end