+
+ def update_timestamps_when_state_changes
+ return if not (state_changed? or new_record?)
+ case state
+ when Running
+ self.started_at ||= Time.now
+ when Failed, Complete
+ self.finished_at ||= Time.now
+ when Cancelled
+ self.cancelled_at ||= Time.now
+ end
+
+ # TODO: Remove the following case block when old "success" and
+ # "running" attrs go away. Until then, this ensures we still
+ # expose correct success/running flags to older clients, even if
+ # some new clients are writing only the new state attribute.
+ case state
+ when Queued
+ self.running = false
+ self.success = nil
+ when Running
+ self.running = true
+ self.success = nil
+ when Cancelled, Failed
+ self.running = false
+ self.success = false
+ when Complete
+ self.running = false
+ self.success = true
+ end
+ self.running ||= false # Default to false instead of nil.
+
+ true
+ end
+
+ def update_state_from_old_state_attrs
+ # If a client has touched the legacy state attrs, update the
+ # "state" attr to agree with the updated values of the legacy
+ # attrs.
+ #
+ # TODO: Remove this method when old "success" and "running" attrs
+ # go away.
+ if cancelled_at_changed? or
+ success_changed? or
+ running_changed? or
+ state.nil?
+ if cancelled_at
+ self.state = Cancelled
+ elsif success == false
+ self.state = Failed
+ elsif success == true
+ self.state = Complete
+ elsif running == true
+ self.state = Running
+ else
+ self.state = Queued
+ end
+ end
+ true
+ end
+
+ def validate_status
+ if self.state.in?(States)
+ true
+ else
+ errors.add :state, "#{state.inspect} must be one of: #{States.inspect}"
+ false
+ end
+ end
+
+ def validate_state_change
+ if self.state_changed?
+ if self.state_was.in? [Complete, Failed, Cancelled]
+ # Once in a finished state, don't permit any changes
+ errors.add :state, "invalid change from #{self.state_was} to #{self.state}"
+ return false
+ elsif self.state_was == Running and not self.state.in? [Complete, Failed, Cancelled]
+ # From running, can only transition to a finished state
+ errors.add :state, "invalid change from #{self.state_was} to #{self.state}"
+ return false
+ end
+ end
+ true
+ end