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Using the HTML5 Tag 303
call to any number of other places in the code, including within the main .ready() function
call, or within the .submit() function.
There is much, much more to error handling, jQuery, and JavaScript than can be shown
in one short chapter, but with this basic knowledge in hand, you can now explore why
the HTML5 tag is so important.
Note If you’d like to learn more about JavaScript and jQuery, the book, JavaScript Step by Step,
provides greater detail with regard to everything you’ve seen in this chapter. Additionally, the
jQuery home page at http://www.jquery.com is an excellent resource for learning about jQuery
and all that it can do.
Using the HTML5 Tag
New in HTML5 is a tag called , which provides a space on which you can draw
graphics, run animations, and much more within a Web page. However, the
tag, by itself, doesn’t do anything. Instead, the tag relies on JavaScript to draw
the graphics it can contain. So you can see that it’s no coincidence that you’ve spent so
much time learning about JavaScript in this chapter!
The tag is one of the easiest tags in HTML5. You simply tell the browser how
large you want the canvas area to be, and it creates the container accordingly. For
example, The following example shows a 250 × 250 pixel :
Unfortunately, as of this writing, many browsers don’t support the element;
therefore, you’ll need to provide alternative content for browsers that aren’t ready for
canvas-based graphics yet. You can provide this alternative content by placing it between
the opening and closing tags, like this:
Alternate content goes here
Browsers that don’t understand the tag will ignore it and display the contents
of the HTML found within it; in this case, a tag.
You use JavaScript to draw on the canvas, so it’s lucky that you just learned so much
about the language!