Nodejs streams Write, Read, Write

Question

Nodejs streams Write, Read, Write

Basically what I'm trying to do is Write to my file from an external source, Read from that file and then re-Write to it with some updated style. I'm doing this to an image. Ex code:

var rawImg = urlHtml('img').attr('src'); // got the image from a website! 

var wStream = request(rawImg).pipe(fs.createWriteStream(__dirname + '/public/img/test.jpg')); //write img to file

var rStream = fs.createReadStream(__dirname + '/public/img/test.jpg', {encoding: 'base64'}); // read img from file
var wStream2 = fs.createWriteStream(__dirname + '/public/img/test-result.jpg') // output

The image does save to file, but anytime I try to read it I always get the error: { [Error: spawn ENOENT] code: 'ENOENT', errno: 'ENOENT', syscall: 'spawn' } - which means its not even there yet

node.js
express
request

Answer 1

You're trying to read the file before it has been created. Try waiting for the file to be closed first:

var wStream = request(rawImg).pipe(fs.createWriteStream(__dirname + '/public/img/test.jpg'));

wStream.on('close', function() {
  var rStream = fs.createReadStream(__dirname + '/public/img/test.jpg', {encoding: 'base64'});
  var wStream2 = fs.createWriteStream(__dirname + '/public/img/test-result.jpg');
});