Tasq

yet another javascript library to manage control flow

It's available on both node and browser

Why flow library - nested callback

// traditional styles
a1(data, function(r1) {
  // some magic
  a2(r1, function(r2) {
  	// some magic
  	a3(r2, function(r3) {
  	  // some magic
      a4(r3, function() {
        // ...
      }
  	}
  }
})

This is how people usually mitigate aforementioned issues

function a1(input) {
    var result = input + ' is';
    return a2(result);
}

function a2(input) {
    var result = input + ' a';
    return a3(result);
}

function a3(input) {
    var result = input + ' nice';
    return a4(result);
}

function a4(input) {
    var result = input + ' person';
    return result;
}

// Tom is a nice person
console.log(a1('Tom'));

It's not easy to consume nested callback by a human brain

In order to make async calls with ease Tasq comes to the rescue

Also, there are tons of control flow libraries in the world which supports Promise/A+

Tasq.queue

Running tasks in given order

function first(data) {
  return data + 5;
}

function second(data) {
  return data * 2;
}

function third(data) {
  return data + 3;
}

function last(data) {
  assert.equal(33, data);
}

var task = Tasq.queue([first, second, third, last]);
task(10);

Should be bound to given context

var a = { name: 'A' },
    b = { name: 'B' },
    c = { name: 'C' },
    say = function() { return this.name; },
    task;

task = Tasq.queue([say.bind(a)]);
task();				// 'A'
task.call(a);		// 'A'

task = Tasq.queue([say.bind(b)]);
task();				// 'B'
task.call(b);		// 'B'

task = Tasq.queue([say]);
task.call(c);		// 'C'
task();				// undefined

How Tasq.queue works

Tasq.async

Running tasks asynchronously

function a() {
  console.log('A');
}

function b() {
  console.log('B');
}

function c() {
  console.log('C');
}

// `callback` is invoked when everything is done successfully
Tasq.async([a, b, c], function callback() {
  console.log("Congrats! Everything is done and let's drink a beer!");
});

Bind context and arguments if indeed

function bindContext() {
  // hello huang47
  console.log('hello ' + this.name);
}

function bindNothing() {
  // hello undefined
  console.log('hello ' + this.name);
}

var o = { name: 'huang47' };

// `callback` is invoked when everything is done successfully
Tasq.async([bindContext.bind(o), bindNothing], function callback() {
  // done
});

How Tasq.async works

YOU ARE WARNED! USE IT AT YOUR OWN RISK

Appendix

npm: tasq

dependencies

unit test

npm: mocha

documentation

npm: yuidocjs

assets are generated from draw.io