CheckList::prepareData

public function prepareData($result)
{
	if(parent::prepareData($result))
	{
		$id = $this->getId();

		if(!$id)
		{
			if(!$this->isFieldModified('CREATED_BY'))
			{
				$this['CREATED_BY'] = $this->getUserId();
			}
		}
		else
		{
			if($this->isFieldModified('IS_COMPLETE'))
			{
				$completeNow = $this['IS_COMPLETE'];
				$completeThen = $this->offsetGetPristine('IS_COMPLETE');
				if($completeNow == 'Y' && $completeThen == 'N')
				{
					if(!$this->isFieldModified('TOGGLED_BY'))
					{
						$this['TOGGLED_BY'] = $this->getUserId();
					}
					if(!$this->isFieldModified('TOGGLED_DATE'))
					{
						$this['TOGGLED_DATE'] = new BitrixMainTypeDateTime();
					}
				}
			}
		}
	}

	return $result->isSuccess();
}