yii2中如何自定义公共类

<? 
namespace appwechat;
class Wechat
{
	const AGENTID = 3;//应用ID
	const CORPID = "wx5d0183ad90c95d8b";//ID
	const CORPSECRET = "KTHAkkVl4mX4Jr_g89d3PXajYupsUcJFvGWQ1K6ZMagTPOh4kiNMfBLFoDr12DVh";//秘钥
	const SCOPE = "snsapi_base"; 
	const STATE = "123"; 	
 
	//自动登录跳转
	public function wxauto($jumpurl){	
	$corpid = self::CORPID; 
	$scope = self::SCOPE; 
	$state = self::STATE; 
	$url='https://open.weixin.qq.com/connect/oauth2/authorize?appid='.$corpid.'
	&redirect_uri='.urlencode($jumpurl).'
	&response_type=code&scope='.$scope.'&state='.$state.'#wechat_redirect';
	header("Location:".$url);
	exit;
	}
	
	//推送信息
	public function getPush($userid , $agentid , $message){
	$userinfo = $this->getToken();//获取access_token
	$access_token = $userinfo['access_token'];
	$sendmsg_url = "https://qyapi.weixin.qq.com/cgi-bin/message/send?access_token=".
	$access_token;
	$data="{"touser":"$userid","msgtype":"text","agentid":$agentid,"text":
	{"content":"$message"},"safe":0}";
	$res = $this->curlPost($sendmsg_url,$data);
	$errmsg=json_decode($res)->errmsg;
	}
	
	//获取token
	public function getToken(){	
	$corpid = self::CORPID; 
	$corpsecret = self::CORPSECRET; 
	$Url="https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=".$corpid."&corpsecret=".$corpsecret;
	$res = $this->curlPost($Url);
	$access_token=json_decode($res)->access_token;
	$userinfo = array();
	$userinfo['access_token']=$access_token;
	return $userinfo;
	}
	
	//定义curl方法
	public function curlPost($url,$data=""){
	$ch = curl_init();
	$opt = array(
	CURLOPT_URL => $url,
	CURLOPT_HEADER => 0,
	CURLOPT_POST => 1,
	CURLOPT_POSTFIELDS => $data,
	CURLOPT_RETURNTRANSFER => 1,
	CURLOPT_TIMEOUT => 20
	);
	$ssl = substr($url,0,8) == "https://" ? TRUE : FALSE;
	if ($ssl){
	$opt[CURLOPT_SSL_VERIFYHOST] = 2; //注意1已经弃用
	$opt[CURLOPT_SSL_VERIFYPEER] = FALSE;
	}
	curl_setopt_array($ch,$opt);
	$data = curl_exec($ch);
	curl_close($ch);
	return $data;
	}
###########**********增加获取微信openid***********#########################
}
?>

	$chat = new Wechat(); //实例化类
	$REDIRECT_URI= $_SERVER['HTTP_HOST'].'/test/back';//定义跳转URL
	$chat->wxauto($REDIRECT_URI);//调用类的方法
 $chat->getToken();//调用类的方法
 
	$corpid = Wechat::CORPID;//调用类的常量
	$corpsecret = Wechat::CORPSECRET;//调用类的常量
	$agentid=Wechat::AGENTID;//调用类的常量