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skin/default/js/lazyload.js

+$.fn.lazyload = function(container, fn) {
+	if (typeof container == "function") {
+		fn = container;
+		container = null;
+	}
+
+	if (!container) container = window;
+	container = $(container);
+
+	if (!fn) fn = $.noop;
+
+	var cache = [];
+
+	//Cached
+	$(this).each(function() {
+		var tag = this.nodeName.toLowerCase(),  url = $(this).data("src");
+		if (url) cache.push({obj:this, tag:this.nodeName.toLowerCase(), url:url});
+		if (tag == "img" && !$(this).attr("src")) $(this).attr("src", "data:image/gif;base64,R0lGODlhAQABAIAAAOjo6AAAACH5BAAAAAAALAAAAAABAAEAAAICRAEAOw==");
+	});
+
+	function check() {
+		var contHeight = container.height();
+		var contop = container.get(0) === window ? container.scrollTop() : container.offset().top;
+
+		$.each(cache, function(i, data) {
+			if (!data.obj) return;
+			var o = $(data.obj), url = data.url;
+
+			var post = o.offset().top - contop;
+			var posb = post + o.height();
+
+			if (o.is(':visible') && (post >= 0 && post < contHeight) || (posb > 0 && posb <= contHeight)) {
+				if (data.tag === "img") {
+					fn.call(o.attr("src", url)[0]);
+				} else {
+					o.load(url, {}, function() {
+						fn.call(o[0]);
+					});
+				}
+
+				data.obj = null;
+			}
+		});
+	}
+
+	check();
+	container.on("scroll", check);
+
+	return this;
+};
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