javascript - 删除云代码中的指针属性

Question

从“MyModel”类中删除一个对象后，下面的代码尝试通过指针属性删除与其相关的两个对象，一个称为“颜色”，一个称为“目标”。这些对象存在于数据中，但日志指示“未找到对象”错误。

代码来源于this answer .

云代码:

function deleteMyModelPointer(myModel, pointerName, pointerClass) {
        var pointer = myModel.get(pointerName);
        if (pointer) {
            var query = new Parse.Query(pointerClass);
            return query.get(pointer).then(function(relatedObject) {
                return relatedObject.destroy();
            });
        } else {
            return null;
        }
    }

    Parse.Cloud.beforeDelete("MyModel", function(request, response) {
        var myModel = request.object;
        deleteMyModelPointer(myModel, "colors", "ColorModel").then(function() {
            return deleteMyModelPointer(myModel , "goal", "Goal");
        }).then(function() {
            response.success();
        }, function(error) {
            response.error(error);
        });
    });

日志:


v14 before_delete 为用户 wMgAGMOPNK 的 MyModel 触发:
输入: {"object":{"ACL":{"wMgAGMOPNK":{"read":true,"write":true}},"colors":{"__type":"Pointer","className":"ColorModel","objectId":"Z3gEplJ0tq"},"counter":1,"createdAt":"2015-12-10T14:06:19.630Z","createdAtLocally":{"__type":"日期","iso ":"2015-12-10T14:06:18.825Z"},"deletedLocally":false,"目标":{"__type":"指针","className":"目标","objectId":"BkruZqhyJ7"},"lastModifiedAt":{"__type":"日期","iso":"2015-12-10T14:06:24.270Z"},"objectId":"LuobH2P8iz","re​​setValue":0,"stepBy":1,"title":"Ggggggg","updatedAt":"2015-12-10T14:06:24.670Z","user":{"__type":"指针","className":"_User","objectId":"wMgAGMOPNK"}}}
结果:{“code”:101，“message”:“找不到对象。”}


但是来自对象浏览器和客户端的两个指针仍然存在。正如我所说，ACL 设置为所有 3 个对象的登录 PFUser(具有读、写权限)。

Answer 1

问题是 OP 代码是为 objectId 属性编写的，而不是指针。有了 objectId，正确的操作是使用 query.get() 来获取相关对象，但对于指针，只需要 fetch 指针(并且不需要知道它的类)。

function deleteMyModelPointer(myModel, pointerName) {
    var pointer = myModel.get(pointerName);
    if (pointer) {
        return pointer.fetch().then(function(relatedObject) {
            return relatedObject.destroy();
        });
    } else {
        return null;
    }
}

调用方可以保持不变，只需删除第三个参数即可。