HTML and CSS Reference
In-Depth Information
itemtype
This attribute is used in conjunction with the
itemscope
attribute in order to define a type
for the microdata item. This is an optional attribute, but if used, it must be placed in the
same element that sets the
itemscope
attribute. The value must be in the form of a URL:
<div itemscope itemtype="http://scores.sports.com/baseball"></div>
<span itemscope itemtype="http://purl.org/vocab/frbr/core#Work"></span>
spellcheck
This attribute is set to either
true
or
false
and indicates whether the content enclosed by
the element should be spelling and grammar checked:
<p spellcheck="true">
How do you spell potatoe? A man named Dan may never
know.
</p>
If it has no value, the assumed value is
true
unless it inherits
false
from an enclosing
parent. The attribute is meaningful on elements that are interactive for text entry, such as
form fields, or elements that have
contenteditable=true
.
tabindex
This attribute, like the
tabindex
attribute initially defined by Internet Explorer, uses a
number to identify the object's position in the tabbing order for keyboard navigation using
the
TAB
key. The attribute should be set to a numeric value. User agents will generally move
through fields with
tabindex
set in increasing numeric order, skipping any elements with 0
or a negative value. After moving over all
tabindex
values, any 0 valued fields will be
navigated in order, but negative values will continue to be skipped. Nonnumeric values will
generally result in the browser applying its normal focusing algorithm.
Event Attributes Reference
In preparation for a more dynamic Web, the W3C has defined a set of core events that
are associated with nearly every (X)HTML element via an event attribute of the style
on
eventname
(for example,
onclick)
. Most of these events cover simple user interaction,
such as the click of a mouse button or the press of a keyboard key. A few elements, such as
form controls, have some special events associated with them. For example, form events
might indicate that the field has received focus from the user or that the form was
submitted. Intrinsic events, such as a document loading and unloading, are also defined. All
the W3C-defined event attributes are described in Table 3-4.
This event model is commonly extended and is not complete. It will certainly change as
HTML5 is implemented and the Document Object Model (DOM) is extended. More
information about the DOM can be found at www.w3.org/DOM. Browser vendors are
already busy paving the way with their own events.
HTML5 Events
The event model defined by HTML5 is still emerging, but the common event-handling
attributes are fairly clear and match most of the HTML 4 events, with some interesting new
