jsPatterns.borrowAndBindProp.js - use apply/call and prototype to implement the function to bind and borrow property from other object.

jsPatterns.borrowAndBindProp.js

/*  # bind() function - 3 impls that works
 *  @ sample:
 *      var newFunc = obj.someFunc.bind(myobj, 1, 2, 3);
 */
 
//pre ECMA5 bind function:

// 《js Pattern》 version
if (typeof Function.prototype.bind === "undefined") {
    Function.prototype.bind = function (thisArg) {
        var fn = this,
            slice = Array.prototype.slice,
            args = slice.call(arguments, 1);
        return function () {
            return fn.apply(thisArg, args.concat(slice.call(arguments)));
        };
    };
}

// 《js ninja》 version
if (typeof Function.prototype.bind === "undefined") {
    Function.prototype.bind = function() {
        var fn = this,
            args = Array.prototype.slice.call(arguments),
            object = args.shift();
        return function() {
            return fn.apply(object,
                args.concat(Array.prototype.slice.call(arguments)));
        };
    };
}

// 《js web application》 version 
if(!Function.prototype.bind){
    Function.prototype.bind = function(obj){
        var slice = [].slice,
            np = function(){},
            args = slice.call(arguments, 1),
            self = this,
            bound = function(){
                return self.apply(this instanceof np? this: (obj || {}),
                args.concat( slice.call(arguments)) );
            };
        np.prototype = self.prototype;
        bound.prototype = new np();
        
        return bound;
    };
}

//test
var one = {
        name: "object",
        say: function (greet) {
            return greet + ", " + this.name;
        }
    },
    two = {
        name: "another object"
    },
    twosay2 = one.say.bind(two),
    twosay3 = one.say.bind(two, 'Enchanté');
    
twosay2('Bonjour'); // "Bonjour, another object

twosay3(); // "Enchanté, another object"