jQuery.localize with string supplanting

gistfile1.js

// sample application-en.json file
/*
{
	Title : "Welcome to {CurrentSite}"
}
*/

if (typeof String.prototype.supplant === 'undefined') {
    String.prototype.supplant = function (o, defaultIfMissing) {
        return this.replace(/{([^{}]*)}/g,
            function (a, b) {
                var r = o[b];
                return typeof r === 'string' || typeof r === 'number' ? r : (defaultIfMissing === undefined ? a : defaultIfMissing);
            }
        );
    };
}

var settings = { CurrentSite = "my website" };

$("[rel*=localize]").localize("application", {
	language: "en",
	pathPrefix: "lang",
	callback: function (data, defaultCallback) {
		var applyFormatting = function (d) {
			for (var key in d) {
				var val = d[key];
				if (typeof val === 'string') {
					var formattedVal = val.supplant(settings, "");
					d[key] = formattedVal;
				} else if (typeof val === 'object') {
					applyFormatting(d[key]);
				}
			}
		};
		applyFormatting(data);
		defaultCallback(data);
	}
});