Keep original content of request.body after express.urlencoded-CodePudding

Is there a way to keep the original text of the request.body after it is passed through and parsed by request.urlecoded?

request.body at any handler after this middleware (app.use(express.urlencoded())) is an object and I can't find any way to get the original raw body that was POSTed to the server.

CodePudding user response：

The server can consume an incoming request only once, because the request body is streamed by the client and the HTTP protocol does not allow the server to request a "rewind" from the client. The express.urlencoded middleware parses the request into an object and express.text parses it into a string. In order to execute both in parallel, you need a "duplexer" that pipes the incoming stream into two streams, one for each middleware to parse.

app.use(function(req, res, next) {
  var url = new stream.PassThrough();
  url.headers = {
    "content-length": req.get("content-length"),
    "content-type": req.get("content-type")
  };
  var text = new stream.PassThrough();
  text.headers = {
    "content-length": req.get("content-length"),
    "content-type": "text/plain"
  };
  req.pipe(new stream.Writable({
    write(chunk, encoding, callback) {
      url.push(chunk);
      text.push(chunk);
      callback();
    },
    destroy(err, callback) {
      url.destroy(err);
      text.destroy(err);
      callback();
    },
    final(callback) {
      url.push(null);
      text.push(null);
      callback();
    }
  }));
  Promise.all([
    new Promise(function(resolve, reject) {
      express.urlencoded({extended: false})(url, res, function() {
        resolve(url.body);
      });
    }),
    new Promise(function(resolve, reject) {
      express.text()(text, res, function() {
        resolve(text.body);
      });
    })
  ]).then(function([urlBody, textBody]) {
    req.urlBody = urlBody;  // parsed into an object
    req.textBody = textBody;  // parsed as the original string
    next();
  });
});

Addendum

After reading the express.urlencoded documentation, I found a simpler solution:

app.use(express.urlencoded({extended: false,
  verify: function(req, res, buf, encoding) {
    req.textBody = buf.toString(encoding);
  }
}));

This makes req.body an object (as usual) and additionally writes the original into req.textBody. But I hope my first attempt is still instructive.