HTML and CSS Reference
Style Attribute Syntax
■ Since the status of each CSS module is ever changing, for complete information about the current status of
each, see the article at http://www.w3.org/Style/CSS/specs .
So the actual CSS3 “specification” is very much a moving target at the moment and browser support for
these specifications will also vary. For example, Microsoft lists the CSS features that they will support in IE 10 in
the article at http://msdn.microsoft.com/en-us/library/ie/hh673536(v=vs.85).aspx . However, there are
already a number of cool features that are generally available and I will demonstrate some of these in Chapter 4 .
Reviewing Other HTML Functionality
The actual scripting syntax is defined by the ECMAScript specification as I mentioned earlier. The current
version, 5.1 was published in June, 2011. While not actually part of the HTML5 specifications, HTML5 compliant
browsers are expected to support the ECMAScript 5.1 standard. As I said, however, this specification describes
the language syntax and some built-in functions such as element selectors.
In addition to the language specification, there are quite a few other specifications that are loosely included
under the HTML5 umbrella that define specific client-side functionality. I will demonstrate many of these in
Chapter 5 and the rest will be covered in later chapters. The new functionality includes:
Offline Cache - you can specify the pages that are required for offline support, including
allow you to monitor and control the local cache.
Drag and Drop - provides the ability to select an item and drop it on another item on the
web page. This will be demonstrated in Chapter 14.
Web workers - allow you to execute a script on a separate thread. This includes
mechanisms to communicate with workers and the ability to share workers between
multiple web pages.
Web storage - includes both
sessionStorage for isolating session data between multiple
tabs connected to the same site as well as localStorage for storing data on the client. The
IndexedDB implementation will be covered in detail in Chapter 11 .
Geolocation - This is not part of the official specifications but has been generally included
when discussing HTML5 features. Geolocation defines an API that can be called from
this is determined by the available hardware. On a GPS-enabled device it will use a GPS
satellite. If GPS support is not available, it will use Wi-Fi, if possible to determine the
location. Mobile devices can use cell tower triangulation. If all else fails, the IP address
can at least provide some estimate of location. Obviously, the accuracy will vary greatly
and the API handles this. I will demonstrate geolocation in Chapter 12 .