微信jssdk分享功能开发及解决ajax跨域的问题

1月9日,腾讯正式面向开发者开放微信内网页开发工具包(微信JS-SDK)，造成以前用js写的微信分享功能都失效了。只好对对着jssdk说明文档重新开发。

微信JS-SDK说明文档

微信JS-SDK Demo

我所要实现的分享功能要求：只要提供一段js代码给前端美工放置在静态页面等就可以实现分享功能。

js代码如下：

<script>
url=location.href;

url = url.replace("&","55555");

//为了解决微信客户端会在你的链接末尾加入其它参数，如果不是动态获取当前链接，将导致分享后的页面签名失败问题。把链接地址中出现的&替换临时字符。否则后台处理就得不到完整的地址链接了。

$.ajax({
type : "get",
url : "http://域名/wx/test/jssdk.PHP?url="+url,
dataType : "jsonp",
jsonp: "callback",
jsonpCallback:"success_jsonpCallback",
success : function(data){
wx.config({
appId: data.appId,
timestamp: data.timestamp,
nonceStr: data.nonceStr,
signature: data.signature,
jsApiList: [
"onMenuShareTimeline",
"onMenuShareAppMessage"
]
});
},
error:function(data){
alert("连接失败！");
}
});
wx.ready(function (){
var shareData = {
title: '霾黄色预警昨发布 冷空气昨夜到温 雾霾可能消散',
desc: '在长大的过程中，我才慢慢发现，我身边的所有事，别人跟我说的所有事，那些所谓本来如此，注定如此的事，它们其实没有非得如此，事情是可以改变的。更重要的是，有些事既然错了，那就该做出改变。',
link: 'http://news.wendu.cn/2015/0127/482049.shtml',
imgurl: 'http://upload.wendu.cn/2015/0127/1422306020538.jpg'
};
wx.onMenuShareAppMessage(shareData);
wx.onMenuShareTimeline(shareData);
});
</script>

为了便于在不同的域名下面页面调用，用了jsonp（json的一种使用模式）来解决跨域数据访问的问题。

url=location.href;获取当前网址，以参数的方式传给jssdk.PHP进行签名验证。 url : "http://域名/wx/test/jssdk.PHP?url="+url

jssdk.PHP是在微信JS-SDK　DEMO的基础上进行了修改。代码如下：

<?PHP
$url = $_GET['url'];

$url = str_replace("55555","&",$url);

//上面JS里&被替换的，在这里要替换回去。 class JSSDK { private $appId; private $appSecret; private $url; public function __construct($appId,$appSecret,$url) { $this->appId = $appId; $this->appSecret = $appSecret; $this->url = $url; } public function getSignPackage() { $jsapiTicket = $this->getJsApiTicket(); $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://"; // $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]"; $url =$this->url; $timestamp = time(); $nonceStr = $this->createNoncestr(); // 这里参数的顺序要按照 key 值 ASCII 码升序排序 $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url"; $signature = sha1($string); $signPackage = array( "appId" => $this->appId,"nonceStr" => $nonceStr,"timestamp" => $timestamp,"url" => $url,"signature" => $signature,"rawString" => $string ); return $signPackage; } private function createNonceStr($length = 16) { $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMnopQRSTUVWXYZ0123456789"; $str = ""; for ($i = 0; $i < $length; $i++) { $str .= substr($chars,mt_rand(0,strlen($chars) - 1),1); } return $str; } private function getJsApiTicket() { // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例 $data = json_decode(file_get_contents("jsapi_ticket.json")); if ($data->expire_time < time()) { $accesstoken = $this->getAccesstoken(); // 如果是企业号用以下 URL 获取 ticket // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accesstoken"; $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accesstoken"; $res = json_decode($this->httpGet($url)); $ticket = $res->ticket; if ($ticket) { $data->expire_time = time() + 7000; $data->jsapi_ticket = $ticket; $fp = fopen("jsapi_ticket.json","w"); fwrite($fp,json_encode($data)); fclose($fp); } } else { $ticket = $data->jsapi_ticket; } return $ticket; } private function getAccesstoken() { // access_token 应该全局存储与更新，以下代码以写入到文件中做示例 $data = json_decode(file_get_contents("access_token.json")); if ($data->expire_time < time()) { // 如果是企业号用以下URL获取access_token // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret"; $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret"; $res = json_decode($this->httpGet($url)); $access_token = $res->access_token; if ($access_token) { $data->expire_time = time() + 7000; $data->access_token = $access_token; $fp = fopen("access_token.json",json_encode($data)); fclose($fp); } } else { $access_token = $data->access_token; } return $access_token; } private function httpGet($url) { $curl = curl_init(); curl_setopt($curl,CURLOPT_RETURNTRANSFER,true); curl_setopt($curl,CURLOPT_TIMEOUT,500); curl_setopt($curl,CURLOPT_SSL_VERIFYPEER,false); curl_setopt($curl,CURLOPT_SSL_VERIFYHOST,CURLOPT_URL,$url); $res = curl_exec($curl); curl_close($curl); return $res; } } $jssdk = new JSSDK("公众号","公众号密钥",$url); $signPackage = $jssdk->GetSignPackage(); $tmp=json_encode(array ('appId'=>$signPackage["appId"],'timestamp'=>$signPackage["timestamp"],'nonceStr'=>$signPackage["nonceStr"],'signature'=>$signPackage["signature"],'url'=>$signPackage["url"])); $callback = $_GET['callback']; echo $callback.'('.$tmp.')'; exit; ?>