我正在使用Mongoose(v.3.8.8)来更新我的模型“Permission”的一些数据。这是架构:
var PermissionSchema = new Schema({
name : {
type: String, required: true, index: true
},
httpVerb : {
type: String, required: true
},
url : {
type: String, required: true
}
});
mongoose.model('Permission', PermissionSchema);
现在我在另一个模块中使用promises函数:
module.exports.updatePermission = function (id, updatedPermission) {
var conditions = {_id: id};
var promiseUpdate = Permission.update(conditions, updatedPermission).exec();
logger.debug('this line is not executed when CastError occurs');
var promiseFind = promiseUpdate.then(function (permission) {
return Permission.findOne(conditions).exec();
}).then(null, function (error) {
logger.info('CastError does not get in here');
logger.error(error);
//error handled here
});
return promiseFind;
}
当我用这个示例参数调用该函数时:
id: 53496a2e1722ff2d1a55a4d2
updatedPermission: {name: 'this is my new name'}
一切正常,因为_id 确实已经存在于集合中。
现在,当我使用以下参数传递无效且不存在的_id:
时id: 53496a2e1722ff2d1a55a4d22
updatedPermission: {name: 'this is my new name'}
我得到以下异常:
CastError: Cast to ObjectId failed for value "53496a2e1722ff2d1a55a4d22" at path "_id"
at ObjectId.cast (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/node_modules/mongoose/lib/schema/objectid.js:116:13)
at ObjectId.castForQuery (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/node_modules/mongoose/lib/schema/objectid.js:165:17)
at Query.cast (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/node_modules/mongoose/lib/query.js:2291:32)
at castQuery (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/node_modules/mongoose/lib/query.js:2015:18)
at Query.update (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/node_modules/mongoose/lib/query.js:1704:21)
at Function.update (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/node_modules/mongoose/lib/model.js:1606:13)
at Object.module.exports.updatePermission (/home/jhon/environment/workspaces/nodejs-workspace/auth/server/app/repository/auth/PermissionRepository.js:50:36)
当承诺被拒绝时,我希望得到此错误,即在updatePermission函数的第二个“ then ”中。
问题是:这是Mongoose的错误吗? - 如何在不使用try / catch的情况下处理此问题?
答案 0 :(得分:0)
在这种特殊情况下,刚刚找到了如何使用promises。 Mongoose有一个函数findOneAndUpdate(http://mongoosejs.com/docs/api.html#model_Model.findOneAndUpdate),它按预期工作。 CastError通过拒绝传递。这样我就可以在没有try / catch块的情况下处理错误。
这是代码(PermissionRepository.js):
module.exports.updatePermission = function (id, updatedPermission) {
var conditions = {_id: id};
var promiseUpdate = Permission.findOneAndUpdate(conditions, updatedPermission).exec();
return promiseUpdate;
}
以下代码调用前一个代码(CastError在第二个“then”中处理):
module.exports.updatePermission = function (req, res) {
var id = req.query.id;
var updatedPermission = req.body;
var permissionRepository = repositoryFactory.getPermissionRepository();
var promise = permissionRepository.updatePermission(id, updatedPermission);
promise.then(function (permission) {
if (!permission) {
res.status(404).json(Error.resourceNotFound);
} else {
res.status(200).json(permission);
}
}).then(null, function (error) {
logger.error(error.stack);
res.status(500).json(Error.databaseError(error.message, error));
});
}
现在我很确定方法更新中存在一个错误(http://mongoosejs.com/docs/api.html#model_Model.update)。我会报告。