bindall-standalone

    1.0.5 • Public • Published

    bindall-standalone

    Allow to permanently mutate an object's method so it context this will always be bound to this object.

    Allow to avoid the non-unbindable listeners registered via emitter.on(foo, this.bar.bind(this));.

    Installation

    npm install bindall-standalone --save

    Then just var bindAll = require('bindall-standalone'). Works with require() e.g. node.js, browserify or component(1).

    API

    bindAll(object, *methods);

    Mutates all methods from object, passed as a list of strings (such as 'foo', 'bar') so they always will be called with the context bound to the object.

    bindAll(object);

    Bind ALL methods available on the object.

    Usage

    Basic example

    var bindAll = require('bindall-standalone');
    
    var object = {
        foo: 10,
        bar: function() {
            return this.foo;
        }
    };
    
    object.bar(); // 10
    
    var func = object.bar;
    func(); // undefined
    
    bindAll(object, 'bar');
    var func = object.bar;
    func(); // 10
    

    Real-world example

    var bindAll = require('bindall-standalone');
    
    var Foo = function() {
        bindAll(this, 'onReady');
    
        // mediator.on('ready', this.onReady.bind(this)); // Never going to be unbinded !
        mediator.on('ready', this.onReady); // No need for explicit 'bind' now !
    };
    
    Foo.prototype.onReady = function() {
        // mediator.off('ready', this.onReady.bind(this)); // That is sad, bro
        mediator.off('ready', this.onReady); // Properly unbinded !
    };
    
    

    What is this

    It used to be a standalone version of underscore's _.bindAll() function for IE9+ browsers. But since bindAll goal is to provide a quick way to bind/unbind methods, and only that, I updated it to use a quicker, more compatible bind function.

    See the underscore source for reference.

    Basically, it avoids this use case:

    mediator.on('foo', this.bar.bind(this));
    mediator.off('foo', this.bar.bind(this));
    // will never be unbinded because this.bar.bind(this) != this.bar.bind(this)
    

    Under the hood

    Since bindAll's only goal is to bind a method to its object context, the bind function can be written as:

    function bind(func, context) {
      return function() {
        return func.apply(context, arguments);
      };
    }
    

    No need for the modern bind function, no need for a polyfill. And it's a lot faster ! Check this jsPerf case.

    Caveats

    There is one significant thing to know: by binding a method on it's object context, it creates an instance-level method. Check this article and this fiddle for more info.

    Install

    npm i bindall-standalone

    DownloadsWeekly Downloads

    6,824

    Version

    1.0.5

    License

    MIT

    Last publish

    Collaborators

    • ayamflow