ListJs.php
public function init()
	{
		parent::init();
		
		if(!isset($this->options['id'])) {
            $this->options['id'] = $this->getId();
        }
		
		if(!isset($this->clientOptions['id'])) {
            $this->clientOptions['id'] = $this->options['id'];
        }
		
		if(empty($this->clientOptions['valueNames'])) {
			throw new InvalidConfigException('The "valueNames" property of "clientOptions" should be set.');
		}
		
		ob_start();
	}
public function init()
	{
		parent::init();
		
		if(!isset($this->options['id'])) {
            $this->options['id'] = $this->getId();
        }
		
		if(!isset($this->clientOptions['id'])) {
            $this->clientOptions['id'] = $this->options['id'];
        }
		
		if(empty($this->clientOptions['valueNames'])) {
			throw new InvalidConfigException('The "valueNames" property of "clientOptions" should be set.');
		}
		
		ob_start();
	}
Initializes the widget.