jquery.imgpreload.js

/**
* jquery.imgpreload 1.6.2 <https://github.com/farinspace/jquery.imgpreload>
* Copyright 2009-2014 Dimas Begunoff <http://farinspace.com>
* License MIT <http://opensource.org/licenses/MIT>
*/
if ('undefined' != typeof jQuery)
{
	(function($){
		'use strict';

		// extend jquery (because i love jQuery)
		$.imgpreload = function (imgs,settings)
		{
			settings = $.extend({},$.fn.imgpreload.defaults,(settings instanceof Function)?{all:settings}:settings);

			// use of typeof required
			// https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Operators/Special_Operators/Instanceof_Operator#Description
			if ('string' == typeof imgs) { imgs = [imgs]; }

			var loaded = [];

			$.each(imgs,function(i,elem)
			{
				var img = new Image();

				var url = elem;

				var img_obj = img;

				if ('string' != typeof elem)
				{
					url = $(elem).attr('src') || $(elem).css('background-image').replace(/^url\((?:"|')?(.*)(?:'|")?\)$/mg, "$1");

					img_obj = elem;
				}

				$(img).bind('load error', function(e)
				{
					loaded.push(img_obj);

					$.data(img_obj, 'loaded', ('error'==e.type)?false:true);

					// http://msdn.microsoft.com/en-us/library/ie/tkcsy6fe(v=vs.94).aspx
					if (settings.each instanceof Function) { settings.each.call(img_obj, loaded.slice(0)); }

					// http://jsperf.com/length-in-a-variable
					if (loaded.length>=imgs.length && settings.all instanceof Function) { settings.all.call(loaded); }

					$(this).unbind('load error');
				});

				img.src = url;
			});
		};

		$.fn.imgpreload = function(settings)
		{
			$.imgpreload(this,settings);

			return this;
		};

		$.fn.imgpreload.defaults =
		{
			each: null, // callback invoked when each image is loaded
			all: null // callback invoked when all images have loaded
		};

	})(jQuery);
}