src/log4php/appenders/LoggerAppenderDailyFile.php
public function activateOptions() {
		parent::activateOptions();
	
		if (empty($this->datePattern)) {
			$this->warn("Required parameter 'datePattern' not set. Closing appender.");
			$this->closed = true;
			return;
		}
	}
public function activateOptions() {
		parent::activateOptions();
	
		if (empty($this->datePattern)) {
			$this->warn("Required parameter 'datePattern' not set. Closing appender.");
			$this->closed = true;
			return;
		}
	}
Additional validation for the date pattern.