HTML and CSS Reference
In-Depth Information
onhelp, onkeydown, onkeypress, onkeyup, onlosecapture, onmouseenter,
onmousedown, onmouseleave, onmousemove, onmouseout, onmouseover, onmouseup,
onmousewheel, onmove, onmoveend, onmovestart, onpaste, onpropertychange,
onreadystatechange, onresizeend, onresizestart, onselectstart, ontimeerror
Element-Specific Attributes
alt
This attribute contains a text string alternative to display in browsers that cannot
display images.
coords
This attribute contains a set of values specifying the coordinates of the hotspot
region. The number and meaning of the values depend upon the value specified for the
shape
attribute. For a
rect
or
rectangle
shape, the
coords
value is two
x,y
pairs:
left
,
top
,
right
, and
bottom
. For a
circ
or
circle
shape, the
coords
value is
x,y,r
,
where
x,y
is a pair specifying the center of the circle and
r
is a value for the radius. For a
poly
or
polygon
shape, the
coords
value is a set of
x,y
pairs for each point in the polygon:
x1,y1,x2,y2,x3,y3,
and so on.
href
This attribute specifies the hyperlink target for the area. Its value is a valid URL.
Either this attribute or the
nohref
attribute must be present in the element.
hreflang
This attribute, introduced by HTML5, is used to indicate the language of the
linked resource in an image map and should be set to whichever language is specified in
the core
lang
attribute. Browsers will likely not annotate links appropriately with language
information, but style sheet rules using attribute selectors could be used to do this. The
absence of this attribute in previous HTML versions is a clear oversight.
media
This HTML5 attribute specifies the media format the link destination was defined
for. It is advisory information, and the value should be used to suggest if a destination is
appropriate for screen, print, PDA, and so on.
name
This attribute is used to define a name for the clickable area so that it can be scripted
by older browsers.
nohref
This attribute indicates that no hyperlink exists for the associated area. Either this
attribute or the
href
attribute must be present in the element. Under XHTML, this attribute
will have a value of
"nohref"
; under standard HTML, no value is required.
ping
This HTML5-specific attribute is used to specify the URL(s) that will be notified
when a link is activated. If more than a single URL is specified, the addresses should be
separated by spaces. Circa early 2009, no browser implements this feature, and privacy
concerns about this attribute may keep it from ever being widely adopted.
rel
HTML5 introduces this attribute to specify link relationships on image maps. The lack
of this attribute in previous specifications was clearly an oversight. For image map areas
containing the
href
attribute, this attribute specifies the relationship of the target object to the
link object. The value is a comma-separated list of relationship values. The values and their
semantics will be registered by some authority that might have meaning to the document
author. The default relationship, if no other is given, is
void
. The
rel
attribute should be used
only when the
href
attribute is present because it makes no sense with
nohref
.
