azure node.js 请求，响应 - 寻求一些澄清

Question

我正在使用 Azure 移动服务-NodeJS 后端，在编写它时，我总是面临这个疑问 - 让我用下面的代码 sn-p 解释一下

//--------------------------------------------------------------------------
function addUserToDB(request, response){
  ///some code here
  var	theUser = request.user;

  ///get the user's entity object
  try {
    objAppUser = buildAppUserEntityObj(theUser, request); //for simplicity sake, lets say this is not asynchronous function
  }
  catch (err) {
    console.log ('error in addUserToDB when calling buildAppUserEntityObj');  //****????****
    request.respond(statusCodes.BAD_REQUEST, err);
    return; // ##????## is a 'return' needed here to avoid the execution of the code below,  or should I assume that the function will return once request is responded (request.respond) in above line.
  }

  ....code to add userEntity to DB
  //some more code in case of successful try above, can I assume there is no way this code will be reached in case of error in the above try-catch
  //       ofcourse I can move this code in the 'try' block above, but I am just trying to understand what happens if above try ends in catch block for some reason and there is no 'return' at the end that catch block.
}

//--------------------------------------------------------------------------
function buildAppUserEntityObj(user, request) {
  if ( user.level === 'anonymous' ) { //ideally this would be called in above function, but I am putting this here just to throw an example.
    console.error('Anonymous User' );
    request.respond(statusCodes.BAD_REQUEST, message);  //will this request.respond will send the response to client immediately, or will it be passed on as error the try-catch of above 'addUserToDB' function 
    return; // ##????## also, is 'return' needed here to avoid the execution of the code below, 
  }

  ....code to build a User entity object based on some business logic
}

//--------------------------------------------------------------------------

我想，这一切都归结为三个问题：
1.这两个地方是否需要'return'（上面两个函数中用##????##标记？
2. 如果 user.level === 'anonymous'
是否会记录消息（由 //****????**** 标记） 3. request.respond 与 response.send 有什么区别？

我相信这些疑问是因为我缺乏全面的 expressJS 知识，所以当我再次浏览 azure/express.js 文档时，我想我会在这里向专家社区提出我的疑问以获得更清晰的解释。

非常感谢。

Answer 1

首先

在第二个return（buildAppUserEntityObj函数的insode，我相信你希望它是：

throw new Error("Anonymous user is not allowed")

否则，即使用户是匿名的，您的catch 代码也永远不会执行。

---

你需要第一个return;，否则会继续执行下面的代码。

第二

如果您修复了第一段中描述的代码，则会记录消息。

第三

标准 Node.js http module 中没有 request.respond。你能澄清一下，你使用的是什么模块？无论如何，该模块的 API 都会回答您的问题。