module ActiveRecord::Timestamp - activerecord-4.2.4 Documentation

# module ActiveRecord::Timestamp

# Active Record Timestamp¶ ↑

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 UTC by default but you can use the local timezone by setting:

    config.active_record.default_timezone = :local

## Time Zone aware attributes¶ ↑

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

### Private Instance Methods

_create_record() click to toggle source
Calls superclass method

    # File lib/active_record/timestamp.rb, line 45
    def _create_record
      if self.record_timestamps
        current_time = current_time_from_proper_timezone

        all_timestamp_attributes.each do |column|
          column = column.to_s
          if has_attribute?(column) && !attribute_present?(column)
            write_attribute(column, current_time)
          end
        end
      end

      super
    end

_update_record(*args) click to toggle source
Calls superclass method

    # 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

all_timestamp_attributes() click to toggle source

    # File lib/active_record/timestamp.rb, line 97
    def all_timestamp_attributes
      timestamp_attributes_for_create + timestamp_attributes_for_update
    end

all_timestamp_attributes_in_model() click to toggle source

    # 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_timestamp_attributes() click to toggle source

Clear attributes and changed_attributes

    # File lib/active_record/timestamp.rb, line 114
    def clear_timestamp_attributes
      all_timestamp_attributes_in_model.each do |attribute_name|
        self[attribute_name] = nil
        clear_attribute_changes([attribute_name])
      end
    end

current_time_from_proper_timezone() click to toggle source

    # File lib/active_record/timestamp.rb, line 109
    def current_time_from_proper_timezone
      self.class.default_timezone == :utc ? Time.now.utc : Time.now
    end

max_updated_column_timestamp(timestamp_names = timestamp_attributes_for_update) click to toggle source

    # File lib/active_record/timestamp.rb, line 101
    def max_updated_column_timestamp(timestamp_names = timestamp_attributes_for_update)
      timestamp_names
        .map { |attr| self[attr] }
        .compact
        .map(&:to_time)
        .max
    end

should_record_timestamps?() click to toggle source

    # File lib/active_record/timestamp.rb, line 73
    def should_record_timestamps?
      self.record_timestamps && (!partial_writes? || changed?)
    end

timestamp_attributes_for_create() click to toggle source

    # File lib/active_record/timestamp.rb, line 93
    def timestamp_attributes_for_create
      [:created_at, :created_on]
    end

timestamp_attributes_for_create_in_model() click to toggle source

    # 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

timestamp_attributes_for_update() click to toggle source

    # File lib/active_record/timestamp.rb, line 89
    def timestamp_attributes_for_update
      [:updated_at, :updated_on]
    end

timestamp_attributes_for_update_in_model() click to toggle source

    # 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