object-bound v0.7.2

object-bound

Convenient replacement for Function.prototype.bind

TL;DR

Replace this

wow.much.dots.so.fancy.very.suit.bind(wow.much.dots.so.fancy.very);
wow.much.dots.so.fancy.very.suit.bind(wow.much.dots.so.fancy.very, '!');
var cached = wow.much.dots.so.fancy.very.suit.bind(wow.much.dots.so.fancy.very);

With this

wow.much.dots.so.fancy.very.bound('suit');
wow.much.dots.so.fancy.very.bound('suit', '!');
wow.much.dots.so.fancy.very.bound.suit;

Usage

Binding

Let's make a bound suit()

var wow = { much: { dots: { so: { fancy: { very: {
  suit: function(suffix) {
    console.log(this.msg + (suffix || ''));
  },
  msg: 'Many compliments'
}}}}}};

To print the following

'Many compliments!'

Function.prototype.bind

var boundSuit = wow.much.dots.so.fancy.very.suit.bind(wow.much.dots.so.fancy.very, '!');
boundSuit(); // 'Many compliments!'

object-bound/function.js

Has all Function.prototype.bind features and a nicer syntax.

var boundSuit = wow.much.dots.so.fancy.very.bound('suit', '!');
boundSuit(); // 'Many compliments!'

object-bound/property.js

Cached function binding. Clears cache on demand. No arguments binding.

var boundSuit = wow.much.dots.so.fancy.very.bound.suit;
boundSuit('!'); // 'Many compliments!'

object-bound/proxy.js

NOTE: Depends on ES6 Proxy, but works for non enumerable functions, unlike object-bound/property.js.

Cached function binding. Clears cache on demand. No arguments binding.

var boundSuit = wow.much.dots.so.fancy.very.bound.suit;
boundSuit('!'); // 'Many compliments!'

Caching

Both property.js and proxy.js cache bound functions and can clear cache on demand.

With caching there is no need to store a reference to the bound function anymore.

var boundSuit1 = wow.much.dots.so.fancy.very.bound.suit;
var boundSuit2 = wow.much.dots.so.fancy.very.bound.suit;

// references the same function, always using .bound.suit gives the same result
boundSuit1 === boundSuit2; // true

Clear cache

Use .bound.bound to get the new cached bound function.

var oldSuit = wow.much.dots.so.fancy.very.bound.suit;

// .bound.bound clears the cache and returns new bound function
var newSuite = wow.much.dots.so.fancy.very.bound.bound.suit;
oldSuit === boundSuit; // false

// references the same function again
newSuite === wow.much.dots.so.fancy.very.bound.suit; // true

Typical property/proxy use case

Cached bound functions simplify working with event listeners.

class Greeter {
  constructor(el) {
    this.el = el;
    this.msg = 'Hi!';
    // no need to store the reference to 'this.bound.hi' somewhere
    this.el.addEventListener('click', this.bound.hi);
  }
  off() {
    // remove event listener using the same 'this.bound.hi'
    this.el.removeEventListener('click', this.bound.hi);
  }
  hi() {
    console.log(this.msg);
  }
}

// get 'Hi!' on each click on the element :)
var greeter = new Greeter(element);

// stop getting 'Hi!' on each click on the element
greeter.off();