jQuery in Action
22
CHAPTER 2
Creating the wrapped element set
parent of the sublists
<li>
elements don't have the class
myList
, as shown in the
Lab results of figure 2.4.
Attribute selectors are also extremely powerful. Say we want to attach a special
behavior only to links that point to locations outside our sites. Let's take another
look at a portion of the Lab example that we previously examined:
look at a portion of the Lab example that we previously examined:
<li><a href="http://jquery.com">jQuery supports</a>
<ul>
<li><a href="css1">CSS1</a></li>
<li><a href="css2">CSS2</a></li>
<li><a href="css3">CSS3</a></li>
<li>Basic XPath</li>
</ul>
</li>
What makes the link pointing to an external site unique is the presence of the
string
string
http://
at the beginning of the value of the link's
href
attribute. We could
select links with an
href
value starting with
http://
with the following selector:
a[href^=http://]
This matches all links with an
href
value beginning with exactly
http://
. The caret
character (
^
) is used to specify that the match is to occur at the beginning of a value.
This is the same character used by most regular expression processors to signify
matching at the beginning of a candidate string; it should be easy to remember.
matching at the beginning of a candidate string; it should be easy to remember.
Visit the Lab page, from which the example
HTML
fragment was lifted, type
a[href^=http://]
into the text box, and click Apply. Note how only the jQuery
link is highlighted.
There are other ways to use attribute selectors. To match an element that pos-
sesses a specific attribute, regardless of its value, we can use
form[method]
Figure 2.4 With the selector
ul.myList
>
li
>
a
, only the direct children of parent nodes
are matched.