fwd-stream

Forward a readable stream to another readable stream or a writable stream to another writable stream. Featuring streams2 support and async instantiating.

npm install fwd-stream

When should I use this?

This module makes it easy to return a stream synchroniously that wraps another stream from an async context. Say for example you wanted to create a folder before writing a write you could do

var fs = require('fs');
var fwd = require('fwd-stream');
 
var ws = fwd.writable(function(cb) {
    fs.mkdir('my-folder', function() {
        cb(null, fs.createWriteStream('my-folder/my-file.txt'));
    });
});
 
ws.write('content of my-file.txt');

Usage

Forward readable streams

var fwd = require('fwd-stream');
 
// rs will be a stream that forwards someReadableStream's data and events
// backpressure etc will still be respected
 
var rs = fwd.readable(someReadableStream);
 
// or using async instantiating
 
var rs = fwd.readable(function(cb) {
    setTimeout(function() {
        cb(null, someReadableStream);
    }, 1000);
});
 
// or using objectMode
 
var rs = fwd.readable({objectMode:true}, someReadableObjectStream);

Forward writable streams

var ws = fwd.writable(someWritableStream);
 
// or using async instantiating
 
var ws = fwd.writable(function(cb) {
    setTimeout(function() {
        cb(null, ws);
    }, 1000);
});
 
// or using objectMode
 
var ws = fwd.writable({objectMode:true}, someWritableObjectStream);

Forward duplex streams

var dupl = fwd.duplex(someWritableStream, someReadableStream);
 
// or using async instantiating
 
var dupl = fwd.duplex(
    function(cb) {
        setTimeout(function() {
            cb(null, someWritableStream);
        }, 1000);
    },
    function(cb) {
        setTimeout(function() {
            cb(null, someReadableStream);
        }, 1000);
    }
);
 
// or using objectMode
 
var dupl = fwd.duplex({objectMode:true}, someReadableObjStream, someWritableObjStream);

License

MIT