YDKJS Soft Bind Polyfill

softBindPolyfill.js

/**
 * The softBind "polyfill" is kind of like .bind(..) hard binding
 * however it is slightly more flexible in that it can allow for
 * `this` overrides with implicit, explicit, and `new` bindings.
 * The default .bind(..) is less flexible only allows `this` overrides
 * in situations where `new` is used.
 *
 * To use it, you pass in some default value for `this`. This value
 * will only be used if the value of `this` at runtime is the global
 * `window` object, or undefined (possibly strict mode). This means
 * implict, explicit, and `new` bindings can override the default value
 * of `this`.
 */

if (!Function.prototype.softBind) {
    Function.prototype.softBind = function(obj) {
        var fn = this,
            curried = [].slice.call( arguments, 1 ),
            bound = function bound() {
                return fn.apply(
                    (!this ||
                        (typeof window !== "undefined" &&
                            this === window) ||
                        (typeof global !== "undefined" &&
                            this === global)
                    ) ? obj : this,
                    curried.concat.apply( curried, arguments )
                );
            };
        bound.prototype = Object.create( fn.prototype );
        return bound;
    };
}