Get download progress in Node.js with request - node.js

Question

I'm creating an updater that downloads application files using the Node module request. How can I use chunk.length to estimate the remaining file size? Here's part of my code:
var file_url = 'http://foo.com/bar.zip';
var out = fs.createWriteStream('baz.zip');
var req = request({
method: 'GET',
uri: file_url
});
req.pipe(out);
req.on('data', function (chunk) {
console.log(chunk.length);
});
req.on('end', function() {
//Do something
});

Answer 1

This should get you the total you want:
req.on( 'response', function ( data ) {
console.log( data.headers[ 'content-length' ] );
} );
I get a content length of 9404541

Answer 2

function download(url, callback, encoding){
var request = http.get(url, function(response) {
if (encoding){
response.setEncoding(encoding);
}
var len = parseInt(response.headers['content-length'], 10);
var body = "";
var cur = 0;
var obj = document.getElementById('js-progress');
var total = len / 1048576; //1048576 - bytes in 1Megabyte
response.on("data", function(chunk) {
body += chunk;
cur += chunk.length;
obj.innerHTML = "Downloading " + (100.0 * cur / len).toFixed(2) + "% " + (cur / 1048576).toFixed(2) + " mb\r" + ".<br/> Total size: " + total.toFixed(2) + " mb";
});
response.on("end", function() {
callback(body);
obj.innerHTML = "Downloading complete";
});
request.on("error", function(e){
console.log("Error: " + e.message);
});
});
};

Answer 3

If you are using "request" module and want to display downloading percentage without using any extra module, you can use the following code:
function getInstallerFile (installerfileURL,installerfilename) {
// Variable to save downloading progress
var received_bytes = 0;
var total_bytes = 0;
var outStream = fs.createWriteStream(installerfilename);
request
.get(installerfileURL)
.on('error', function(err) {
console.log(err);
})
.on('response', function(data) {
total_bytes = parseInt(data.headers['content-length']);
})
.on('data', function(chunk) {
received_bytes += chunk.length;
showDownloadingProgress(received_bytes, total_bytes);
})
.pipe(outStream);
};
function showDownloadingProgress(received, total) {
var platform = "win32"; // Form windows system use win32 for else leave it empty
var percentage = ((received * 100) / total).toFixed(2);
process.stdout.write((platform == 'win32') ? "\033[0G": "\r");
process.stdout.write(percentage + "% | " + received + " bytes downloaded out of " + total + " bytes.");
}
Usage :
getInstallerFile("http://example.com/bar.zip","bar.zip");

Answer 4

Using the cool node-request-progress module, you could do something like this in es2015:
import { createWriteStream } from 'fs'
import request from 'request'
import progress from 'request-progress'
progress(request('http://foo.com/bar.zip'))
.on('progress', state => {
console.log(state)
/*
{
percentage: 0.5, // Overall percentage (between 0 to 1)
speed: 554732, // The download speed in bytes/sec
size: {
total: 90044871, // The total payload size in bytes
transferred: 27610959 // The transferred payload size in bytes
},
time: {
elapsed: 36.235, // The total elapsed seconds since the start (3 decimals)
remaining: 81.403 // The remaining seconds to finish (3 decimals)
}
}
*/
})
.on('error', err => console.log(err))
.on('end', () => {})
.pipe(createWriteStream('bar.zip'))

Answer 5

In case someone wants to know the progress without the use of other library but only request, then you can use the following method :
function downloadFile(file_url , targetPath){
// Save variable to know progress
var received_bytes = 0;
var total_bytes = 0;
var req = request({
method: 'GET',
uri: file_url
});
var out = fs.createWriteStream(targetPath);
req.pipe(out);
req.on('response', function ( data ) {
// Change the total bytes value to get progress later.
total_bytes = parseInt(data.headers['content-length' ]);
});
req.on('data', function(chunk) {
// Update the received bytes
received_bytes += chunk.length;
showProgress(received_bytes, total_bytes);
});
req.on('end', function() {
alert("File succesfully downloaded");
});
}
function showProgress(received,total){
var percentage = (received * 100) / total;
console.log(percentage + "% | " + received + " bytes out of " + total + " bytes.");
// 50% | 50000 bytes received out of 100000 bytes.
}
downloadFile("https://static.pexels.com/photos/36487/above-adventure-aerial-air.jpg","c:/path/to/local-image.jpg");
The received_bytes variable saves the total of every sent chunk length and according to the total_bytes, the progress is retrieven.

Answer 6

I wrote a module that just does what you want: status-bar.
var bar = statusBar.create ({ total: res.headers["content-length"] })
.on ("render", function (stats){
websockets.send (stats);
})
req.pipe (bar);