Async fluent javascript (node) interface (using deferreds)

Question

What is the best way to build fluent interface in Javascript (node.js) with

obj.function1().function2().function3();

where functions are asynchronous methods?

There is a module called chainsaw, but if it is possilble to do with deferreds and promises (https://github.com/kriskowal/q)

UPD: chain with q.js

obj.function1().then(obj.function2) 
//inside obj.function2 "this" context is lost, 
//and code is actually broken

obj.function1().then(funciton(){
  obj.function2() // <-- "this" context is OK
}) 

Answer 1

Deferred implementation allows you to do something close, with invoke:

obj.function1().invoke('function2').invoke('function3');

When ES6 proxies will become a reality, there is a plan to allow same functionality with code below

obj.function1().function2().function3();

but we're not there yet.

Also worth noting is that in Deferred promise object is actually a function which equals to promise.then. So plain functions can be chained as:

function1()(function2)(function3);

I hope that's helpful