wx_sample.php

<?php
/**
  * wechat php test
  */

//define your token
define("TOKEN", "weixin");
$wechatObj = new wechatCallbackapiTest();
$wechatObj->valid();

class wechatCallbackapiTest
{
	public function valid()
    {
        $echoStr = $_GET["echostr"];
		
        //valid signature , option
      /*   if($this->checkSignature()){
        	echo $echoStr;
        	exit;
        } */
		
		if($this->checkSignature() && $echoStr){
			//第一次接入weixin api接口的时侯
			echo $echoStr;
			exit;			
		}else{
			//关注时触发回复
			$this->responseMsg();
		}

    }
	
	//接收事件并回复
    public function responseMsg()
    {
		//get post data, May be due to the different environments
		$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];

      	//extract post data
		if (!empty($postStr)){
                /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,
                   the best way is to check the validity of xml by yourself */
                libxml_disable_entity_loader(true);
              	$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
                $fromUsername = $postObj->FromUserName;
                $toUsername = $postObj->ToUserName;
                $keyword = trim($postObj->Content);
                $time = time();
                $textTpl = "<xml>
							<ToUserName><![CDATA[%s]]></ToUserName>
							<FromUserName><![CDATA[%s]]></FromUserName>
							<CreateTime>%s</CreateTime>
							<MsgType><![CDATA[%s]]></MsgType>
							<Content><![CDATA[%s]]></Content>
							<FuncFlag>0</FuncFlag>
							</xml>";             
				if(!empty( $keyword ))
                {
              		$msgType = "text";
                	$contentStr = "Welcome to wechat world!";
                	$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
                	echo $resultStr;
                }else{
                	echo "Input something...";
                }

				//用户发送tuwen1关键字的时候，回复一个单图文
				/* if(strtolower($postObj->MsgType)=='text' && strtolower($postObj->content)=='tuwen1'){
					$toUser = $postObj->FromUserName;
					$fromUser = $postObj->ToUserName;
					$arr = array(
						array('title'=>'imooc',
						'description'=>'imooc is good',
						'picUrl'=>'imooc',
						'url'=>'imooc',)
					);	
					
					$template="
					<xml>
					<ToUserName><![CDATA[%s]]></ToUserName>
					<FromUserName><![CDATA[%s]]></FromUserName>
					<CreateTime>%s</CreateTime>
					<MsgType><![CDATA[%s]]></MsgType>
					<ArtileCount>".count($arr)."</ArtileCount>
					<Articles>";
					foreach($arr as $k=>$v){					
						$template.="<item>
							<Title><![CDATA[".$v['title']."]]></Title>
							<Description><![CDATA[".$v['description']."]]></Description>
							<PicUrl>![CDATA[".$v['picurl']."]]</PicUrl>
							<Url><![CDATA[".$v['url']."]]></Url>
						</item>";
					}
					$template.="</Articles>
					</xml>";
					echo sprintf($template,$toUser,$fromUser,time(),'news');
				} */
				
        }else {
        	echo "";
        	exit;
        }
    }
		
	private function checkSignature()
	{
        // you must define TOKEN by yourself
        if (!defined("TOKEN")) {
            throw new Exception('TOKEN is not defined!');
        }
        
        $signature = $_GET["signature"];
        $timestamp = $_GET["timestamp"];
        $nonce = $_GET["nonce"];
        		
		$token = TOKEN;
		$tmpArr = array($token, $timestamp, $nonce);
        // use SORT_STRING rule
		sort($tmpArr, SORT_STRING);
		$tmpStr = implode( $tmpArr );
		$tmpStr = sha1( $tmpStr );
		
		if( $tmpStr == $signature ){
			return true;
		}else{
			return false;
		}
	}
}

?>