jquery.format.js

/**
 *	jQuery string format plugin
 *  http://github.com/krzyzak00/format
 *
 *  Copright (c) 2011 Przemysław Kościelniak
 *  Dual licensed under the MIT and GPL
 *
 *	Adds Python-like format function to jQuery
 *	This is basic implementation and it doesn't cover all Python format features
 *	@param {string} string
 *	@param {mixed} variables
 *	@return {string} formated string
 */

/*
	Usage examples:

	$.fn.format('The quick {} {} jumped over the {} {}', "brown", "fox", "lazy", "dog");
	$.fn.format('The quick {0} {2} jumped over the {1} {3}', "brown", "lazy", "fox", "dog");
	$.fn.format('The quick {_brown_} {_fox_} jumped over the {_lazy_} {_dog_}', {
		_brown_: "brown",
		_fox_: "Fox",
		_lazy_: "lazy",
		_dog_: "Dog"
	});
	$.fn.format('The quick {0} {1} jumped over the {2} {3}', {
		0: "brown",
		1: "fox",
		2: "lazy",
		3: "dog"
	});
*/

(function (factory) {

    if (typeof define === 'function' && define.amd) {
        // AMD. Register as an anonymous module.
        define(['jquery'], factory);
    } else {
        // Browser globals
        factory(jQuery);
    }

}(function ($) {

    $.fn.format = function() {

		var isArguments = function(obj) {
			return obj.constructor !== String && obj.constructor !== Array && obj.length;
		};

		var args = isArguments(arguments[0]) ? arguments[0] : arguments,
			alen = args.length;

		// no arguments given
		if (!alen) { return null; }

		// if only one argument given assume it's string and simply return it
		else if (alen === 1) { return args[0]; }

		// second argument is either variable or object with named vars
		else {

			var str = args[0],
				matches = str.match(/{[^}]*}/g),
				mlen = matches ? matches.length : 0,
				i = 0,
				name, val, r;

			// for object with named variables
			if (typeof(args[1]) === 'object') {

				while (i < mlen) {

					name = matches[i].replace(/{/, '').replace(/}/, '');
					val = args[1][name];
					var rs = '';

					if (isNaN(parseInt(name, 10))) {
						rs = "{" + name + "}";
					} else {
						rs = "{[" + i + "]}";
					}

					r = new RegExp(rs, "g");
					str = str.replace(r, args[1][name]);

					i++;
				}

				return str;

			} else { // for variables as arguments

				if (!matches || matches.length !== alen - 1) {
					throw "Format: wrong number of arguments, " + str;
				}

				while (i < alen - 1) {

					// replace {} {} {} ... {}
					if (matches[i].length === 2) {
						str = str.replace('{}', args[i + 1]);
					}

					// replace {0} {1} {2} ... {n}
					else {

						r = new RegExp("{[" + i + "]}", "g");
						str = str.replace(r, args[i + 1]);
					}

					i++;
				}

				return str;
			}
		}
	};
}));