Using POST data to write to local file with node.js and express

Question

I'm trying to just handle simple POST requests and append the data to a local file. However, when I try to POST raw text with postman, such as 'hi world', what's actually appended is [object Object]. I'm not sure what could be causing this if nothing should be interpreted as an object on either end. Thank you!

var express = require('express'),
    fs = require('fs')
    url = require('url');
var app = express();

app.configure(function(){
  app.use('/public', express.static(__dirname + '/public'));  
  app.use(express.static(__dirname + '/public')); 
  app.use(express.bodyParser());
});

app.post('/receive', function(request, respond) {
    filePath = __dirname + '/public/data.txt';
    fs.appendFile(filePath, request.body, function () {
        respond.end();
    });
});

app.listen(8080);

Since you're using bodyParser req.body is (I assume always) an object. I've got no idea how postman works but shouldn't any data you're trying to send be named (eg req.body.param)? — Andreas Hultgren, Jul 31 '13 at 22:00

score 21 · Accepted Answer · edited Nov 16 '20 at 00:14

21

var express = require('express'),
    fs = require('fs'),
    url = require('url');
var app = express();

app.use('/public', express.static(__dirname + '/public'));  
app.use(express.static(__dirname + '/public')); 

app.post('/receive', function(request, respond) {
    var body = '';
    filePath = __dirname + '/public/data.txt';
    request.on('data', function(data) {
        body += data;
    });

    request.on('end', function (){
        fs.appendFile(filePath, body, function() {
            respond.end();
        });
    });
});

app.listen(8080);

edited Nov 16 '20 at 00:14

Jake A. Smith

2,278
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answered Jul 31 '13 at 22:50

user4815162342

1,638
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2

app.configure is now deprecated, but this code works if you comment out line 6 and 9. – dirkk0 Sep 26 '14 at 09:40
1

Why not just `request.pipe(fs.createWriteStream(filePath, {flags:'a'}))` – masterxilo Mar 08 '18 at 08:24

score 5 · Answer 2 · answered Jul 31 '13 at 22:12

If you want to do POST requests with regular urlencoded bodies, you don't want to use bodyParser (since you don't actually want to parse the body, you just want to stream it to the filesystem). Consider just streaming the chunks of data with req.pipe(writeableStreamToYourFile).

If you want to do file uploads, you can use bodyParser for that, but it handles multiple files and writes them to disk for you and you would need to iterate through req.files and copy them from a temporary directory to your target file.

This turned a 10-line function into a 1-liner. So much cruft, so little time... No need for busboy either. — user1944491, Apr 22 '21 at 13:08

score 4 · Answer 3 · answered Mar 02 '17 at 03:35

If you want to store Json data then file should be of **.Json type. Otherwise try casting it into string and write into **.txt file. Like

var fs = require('fs');
var writer = fs.createWriteStream('output.txt');
response = {
name: '',
id: ''
}
writer.write(JSON.stringify(response));

Using POST data to write to local file with node.js and express

3 Answers3

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