ftp client with async javascript

Question

I'm writing in node.js and using async.js and ftp client modules.
I'm using async.series and that is a function in async.series:

    var client = new ftp();
client.on('ready', function () {
    for ( var i = 0  ; i < stage._sub_directories.length ; i++ ) {
        var path = get_absolute_path() + DIRECTORY_NAME_LESSONS + stage._name + "/" + DIRECTORY_NAME_STAGE + stage._sub_directories[i];
        var file = 'copy.' + stage._sub_directories[i] + get_xml_file_name();
        client.get(path + "/" + get_xml_file_name(), function (err, stream) {
            console.log('done');
            if (err) throw err;
            stream.once('close', function () {client.end();});
            stream.pipe(fs.createWriteStream(file));
            callback(null, true);
        });
    }
});
client.connect(config);

the callback(null, true); is for async module. When it's run, its insert into for loop stage._sub_directories.length times, and then insert to client.get() just one time (last time).
it's created one file and not more.
what is my problem? I should use another async control flow? or something else?

Answer 1

The way your code is written, it won't work, because you're calling an asynchronous function, client.get, inside a regular loop.

You should replace your regular for loop for the async.eachSeries method, since you're already using async.js. Try this:

client.on('ready', function () {
    async.eachSeries(stage._sub_directories, function (subDir, done) {
        var path = get_absolute_path() + DIRECTORY_NAME_LESSONS + stage._name + "/" + DIRECTORY_NAME_STAGE + subDir;
        var file = 'copy.' + subDir + get_xml_file_name();
        client.get(path + "/" + get_xml_file_name(), function (err, stream) {
            if (err) return done(err);
            console.log('done');
            stream.once('close', function () {client.end();});
            stream.pipe(fs.createWriteStream(file));
            done();
        });
    }, function (err) {
        if (err) return callback(err);
        callback(null, true);
    });
});