Node.js进度指示器反馈 [英] Node.js progress indicator feedback

问题描述

我对使用Node.js'请求'发送的进度有疑问。我有一个Node.js应用程序充当代理，实际上将一个主体转发到另一个服务器。我希望看到此上传操作的进度。现在我这样做：

I have a question about the progress of sending with Node.js 'request'. I have a Node.js application that acts as a proxy, actually forwarding a body to another server. I want to see the progress of this upload action. Now I am doing this:

BROWSER 
   -> UPLOAD TO NODE 
   -> UPLOAD TO 3rd PARTY SERVICE 
   -> RETURN 3rd PARTY RESPONSE TO BROWSER

如果可以的话，我会记录它以检查控制台。记录已完成的进度。但是，是否也可以返回

If this is possible, I would log it to check in the console.log how much progress is done. But, would it also be possible to return a

res.send(progress)

同时等待上传完成并发回客户端上传成功了吗？

in the mean time, while waiting for the upload to finish and send the client back the upload has succeeded?

BROWSER 
   -> UPLOAD TO NODE
   -> UPLOAD TO 3rd PARTY SERVICE 
       -> RETURN progress <- 
       -> RETURN progress <- 
       ...etc.
   -> RETURN 3rd PARTY RESPONSE TO BROWSER

这是上传代码（非常简单）。

This is the upload code (pretty much straightforward).

var requestOptions = {
    timeout: 120000,
    url: url, //URL to hit
    method: 'post',
    headers: headers,
    body: payload //Set the body as a string
};


request(requestOptions, function (error, response, body) {
    if (error) {
        res.send(error);
    }
    else {
        //res.sendStatus(response.statusCode);
        console.log("[RETURNING RESPONSE BODY]");
        res.send(body);
    }
});

推荐答案

您的问题包含两部分。一个是从请求中获取进度，可以在此处找到：上传进度 - 请求

Your question contains two parts. One is for getting the progress from request, which can be found here: Upload Progress — Request

另一部分是通知浏览器进度。 HTTP协议不允许您发送多个响应，因此无法使用 res.send（progress）。

The other part would be notifying the browser of the progress. The HTTP protocol does not let you send multiple responses, so using res.send(progress) is not possible.

但是，您可以继续发送部分响应，直到完成为止。在不关闭它的情况下写入res就像 res.write（string）一样简单，但访问响应可能更难：使用AJAX或WebSockets访问部分响应？

However, you can keep sending partial responses until it finishes. Writing something to res without closing it is as simple as res.write("string"), but accessing the response can be harder: Accessing partial response using AJAX or WebSockets?

您还需要一种方法来从支持服务器包装正文（以及错误），以便它可以作为最终的部分响应。

You also need a way to wrap the body (and also errors) from the backing server so that it can fit as the final partial response.

另一种解决方案是打开另一个WebSocket请求跟踪上传/下载过程。 socket.io是一个很好的节点库，用于此目的。

Another solution would be opening another WebSocket request to track the uploading/downloading process. socket.io is a good library for node for this purpose.

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