jQuery中jsonp的跨域处理,no access-control-allow-origin,unexpected token

引言

ajax跨域就无法成功获取数据了，需要通过jsonp来处理

报错如下

1.改为jsonp

    var targeturl = ajaxurl+"?g=Api&m="+m+"&a="+a; // 跨域地址
    $.ajax({
        type: "get",
        url:targeturl,
        async:false, // 不支持同步，同步无效
        dataType:'jsonp',
        jsonp: "callback",
        jsonpCallback:"jsonpHandler",
        data: {},
        success:function(json){
        }
    });

这个时候，还不够。依旧无法获取json数据

报错如下

2.需要后台处理

原输出格式

protected function printOut() {
    exit(json_encode($this->outData));
}

改为新的格式,加上一个callback

protected function printJsonp() {
    exit($_GET['callback']."(".json_encode($this->outData).")");
}

在XHR中并不能看到

它其实属于js范畴，会自动包裹上回调函数名，

jsonpHandler({"status":1,"msg":"\u83b7\u53d6\u6210\u529f","info":[{"id":"1","name":"\u8863\u670d","goods":[{"goods_id":"1","name":"\u6f02\u4eae\u7684\u8863\u670d","price":"100","logoimg":"http:\/\/image.diandodo.com\/zhudianbao\/Uploads\/User\/u1250000222\/20160723\/201607231342158687.png@250h_250w_1e_1c"},{"goods_id":"2","name":"\u7f8e\u4e3d\u7684\u8863\u670d","price":"200","logoimg":"http:\/\/image.diandodo.com\/zhudianbao\/Uploads\/User\/u1250000222\/20160723\/201607231342158687.png@250h_250w_1e_1c"}]},{"id":"2","name":"\u978b\u5b50","goods":[{"goods_id":"3","name":"\u6f02\u4eae\u7684\u978b\u5b50","price":"100","logoimg":"http:\/\/image.diandodo.com\/zhudianbao\/Uploads\/User\/u1250000222\/20160723\/201607231342158687.png@250h_250w_1e_1c"},{"goods_id":"4","name":"\u7f8e\u4e3d\u7684\u978b\u5b50","price":"200","logoimg":"http:\/\/image.diandodo.com\/zhudianbao\/Uploads\/User\/u1250000222\/20160723\/201607231342158687.png@250h_250w_1e_1c"}]}]})

3.jsonp不支持同步处理，需要异步处理。

jsonp中async无效。要么把操作写在success中，要么写在回调函数中。

    // ajax获取接口数据
    ajaxGetApiInfo('Home','getCategoryGoods');
    function jsonpHandler(json) {
        if (json.status == '1') {
            var goods = json.info;
            var evalText = doT.template($("#category-goods-tmpl").text());
            $("#category-goods").html(evalText(goods));
        }
    }