Added in support for basic JSON object parsing of data- attributes.

src/data.js

@@ -1,7 +1,8 @@
(function( jQuery ) {

var windowData = {},
	rnum = /^-?\d+(?:\.\d+)$/;
	rnum = /^-?\d+(?:\.\d+)$/,
	rbrace = /^{.*}$/;

jQuery.extend({
	cache: {},
@@ -153,11 +154,14 @@ jQuery.fn.extend({
					data = this[0].getAttribute( "data-" + key );

					if ( typeof data === "string" ) {
						data = data === "true" ? true :
							data === "false" ? false :
							data === "null" ? null :
							rnum.test( data ) ? parseFloat( data ) :
							data;
						try {
							data = data === "true" ? true :
								data === "false" ? false :
								data === "null" ? null :
								rnum.test( data ) ? parseFloat( data ) :
								rbrace.test( data ) ? jQuery.parseJSON( data ) :
								data;
						} catch( e ) {}

					} else {
						data = undefined;

test/unit/data.js

@@ -158,7 +158,7 @@ test(".data(String) and .data(String, Object)", function() {
});

test("data-* attributes", function() {
	expect(22);
	expect(23);
	var div = jQuery("<div>"),
		child = jQuery("<div data-myobj='old data' data-ignored=\"DOM\"></div>");

@@ -186,6 +186,7 @@ test("data-* attributes", function() {
		.attr("data-point", "5.5")
		.attr("data-pointbad", "5..5")
		.attr("data-pointbad2", "-.")
		.attr("data-badjson", "{123}")
		.attr("data-null", "null")
		.attr("data-string", "test");

@@ -195,6 +196,7 @@ test("data-* attributes", function() {
	equals( child.data('point'), 5.5, "Primitive number read from attribute");
	equals( child.data('pointbad'), "5..5", "Bad number read from attribute");
	equals( child.data('pointbad2'), "-.", "Bad number read from attribute");
	equals( child.data('badjson'), "{123}", "Bad number read from attribute");
	equals( child.data('null'), null, "Primitive null read from attribute");
	equals( child.data('string'), "test", "Typical string read from attribute");

@@ -213,7 +215,7 @@ test("data-* attributes", function() {
			break;
		case 2:
			equals(jQuery(elem).data("zoooo"), "bar", "Check zoooo property");
			equals(jQuery(elem).data("bar"), '{"test":"baz"}', "Check bar property");
			same(jQuery(elem).data("bar"), {"test":"baz"}, "Check bar property");
			break;
		case 3:
			equals(jQuery(elem).data("number"), true, "Check number property");