get-bound-func

A tiny library that simplifies function binding and reduces unnecessary function binds.

Compatible with AMD, CommonJS, ES6 imports, and global HTML tag inclusion.

Changelog

Install

$ npm install --save get-bound-func

Usage

CodePen Example

ES6 Modules

import getBoundFunc, { deleteBoundFuncs } from 'get-bound-func';


class MyClass {

  constructor(msg) {
    this.val = msg;
  }

  onClick(e) {
    console.log(this.val);
  }

  registerOnClick(element) {
    element.addEventListener('click', getBoundFunc(this, this.onClick));
  }
}


const obj0 = new MyClass("Fish fingers and custard");
const obj1 = new MyClass(42);

const myElement = document.getElementById('myElement');

obj0.registerOnClick(myElement);
obj1.registerOnClick(myElement);


myElement.click(); // Will output `Fish fingers and custard` and `42` to console


// NOTE: It is NOT always required to call `deleteBoundFuncs`.
// See API docs of `deleteBoundFuncs` for details.
deleteBoundFuncs(obj0); // Clears all `obj0` bound functions from memory
deleteBoundFuncs(obj1); // Clears all `obj1` bound functions from memory

CommonJS

const getBoundFunc = rquire('get-bound-func');


function MyClass(msg) {
  this.val = msg;
}

MyClass.prototype.onClick = function(e) {
  console.log(this.val);
}

MyClass.prototype.registerOnClick = function(element) {
  element.addEventListener('click', getBoundFunc(this, this.onClick));
}


var obj0 = new MyClass("Fish fingers and custard");
var obj1 = new MyClass(42);

var myElement = document.getElementById('myElement');

obj0.registerOnClick(myElement);
obj1.registerOnClick(myElement);


myElement.click(); // Will output `Fish fingers and custard` and `42` to console


// NOTE: It is NOT always required to call `deleteBoundFuncs`.
// See API docs of `deleteBoundFuncs` for details.
getBoundFunc.deleteBoundFuncs(obj0); // Clears all `obj0` bound functions from memory
getBoundFunc.deleteBoundFuncs(obj1); // Clears all `obj1` bound functions from memory

API

getBoundFunc(context, func)

Creates a new bound function of func that is bound to context and caches the result. If getBoundFunc has already been called for the given context and func, then the cached bound function is returned.

Parameters

• context (*) The context of the returned bound function (I.E. context will equal this within the scope of the bound function).
• func (Function) The function to be bound.

Returns

A version of func that is bound to context.

Type: Function

deleteBoundFunc(context)

Clears from memory all cached bound functions for the given context.

NOTE: It is not always required to use this function to clear cached bound functions. Behind the scenes, WeakMaps are used to store the cached bound functions, therefore, whenever all other references to the context object have been removed, the context's corresponding bound functions in the cache will automatically be cleared for you. However, this function has been made available in the case that you want to manually clear the cache so that memory is freed up sooner, or in instances where the context will not be garbage collected.

For more information, refer to the MDN documentation on WeakMap.

Parameters

• context (*) The context of the bound functions that will be removed from memory.

License

ISC License (ISC)

Copyright (c) 2017, Brandon D. Sara (http://bsara.pro/)

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.