As you learn HTML5 and add new techniques to your toolbox, you’re likely going to want to build yourself a blueprint, or boilerplate, from which you can begin all your HTML5-based projects. In fact, you’ve probably already done something similar for your existing XHTML or HTML 4.0 projects.
We encourage this, and you may also consider using one of the many online sources that provide a basic HTML5 starting point for you.
In this project, however, we want to build our code from scratch and explain each piece as we go along. Of course, it would be impossible for even the most fantastical and unwieldy sample site we could dream up to include every new element or technique, so we’ll also explain some new features that don’t fit into the project. This way, you’ll be familiar with a wide set of options when deciding how to build your HTML5 and CSS3 websites and web apps, so you’ll be able to use this book as a quick reference for a number of techniques.
Let’s start simple, with a bare-bones HTML5 page:
The HTML5 Herald
Look closely at the above markup. If you’re making the transition to HTML5 from XHTML or HTML 4, then you’ll immediately notice quite a few areas in which HTML5 differs.
The Doctype
First, we have the Document Type Declaration, or doctype. This is simply a way to tell the browser—or any other parsers—what type of document they’re looking at. In the case of HTML files, it means the specific version and flavor of HTML. The doctype should always be the first item at the top of all your HTML files. In the past, the doctype declaration was an ugly and hard-to-remember mess. For XHTML 1.0 Strict:
And for HTML4 Transitional:
Over the years, code editing software began to provide HTML templates with the doctype already included, or else they offered a way to automatically insert one. And naturally, a quick web search will easily bring up the code to insert whatever doctype you require.
Although having that long string of text at the top of our documents hasn’t really hurt us (other than forcing our sites’ viewers to download a few extra bytes), HTML5 has done away with that indecipherable eyesore. Now all you need is this:
Simple, and to the point. You’ll notice that the “5” is conspicuously missing from the declaration. Although the current iteration of web markup is known as “HTML5,” it really is just an evolution of previous HTML standards—and future specifications will simply be a development of what we have today. Because browsers have to support all existing content on the Web, there’s no reliance on the doctype to tell them which features should be supported in a given document.
The html Element
Next up in any HTML document is the html element, which has not changed significantly with HTML5. In our example, we’ve included the lang attribute with a value of en, which specifies that the document is in English. In XHTML-based syntax, you’d be required to include an xmlns attribute. In HTML5, this is no longer needed, and even the lang attribute is unnecessary for the document to validate or function correctly.
So here’s what we have so far, including the closing