class User extends Authenticatable implements MustVerifyEmail
{
    use Notifiable;

    const SLACK_CHANNEL_WWW = 'xxx';
    const SLACK_CHANNEL_BACKEND = 'xxx';

    protected $slackChannels= [
        self::SLACK_CHANNEL_WWW,
        self::SLACK_CHANNEL_BACKEND,
    ];

    protected $slack_url = null;

    /**
     * Specify Slack Webhook URL to route notifications to
     *
     * @return string
     */
    public function routeNotificationForSlack(){
        if($this->slack_url === null){
            return self::SLACK_CHANNEL_WWW;
        }

        return $this->slack_url;
    }

    /**
     * @param $name
     * @return $this
     */
    public function setSlackChannel($name){
        if(in_array($name, $this->slackChannels)){
            $this->setSlackUrl($name);
        }

        return $this;
    }

    /**
     * @param $url
     * @return $this
     */
    public function setSlackUrl($url){
        $this->slack_url = $url;

        return $this;
    }
}

//    $user = User::find(1);
//    $user->setSlackChannel(User::SLACK_CHANNEL_WWW)->notify(new ShopCreated());