Java Reference
In-Depth Information
targetImage="mapImage" />
<bookstore:area id="map2" value="#{Book202}"
onmouseover="resources/images/book_202.jpg"
onmouseout="resources/images/book_all.jpg"
targetImage="mapImage"/>
...
</bookstore:map>
...
</h:form>
The
alt
attribute of the
h:graphicImage
tag maps to the localized string “
Choose
a Book from our Catalog
”.
The
f:actionListener
tag within the
bookstore:map
tag points to a listener
class for an action event. The
processAction
method of the listener places the topic
ID for the selected map area into the session map. The way this event is handled is ex-
plained more in “
Handling Events for Custom Components
” on page
119
.
The
action
attribute of the
bookstore:map
tag specifies a logical outcome
String
,
“
bookstore
”, which by implicit navigation rules sends the application to the page
bookstore.xhtml
. For more information on navigation, see the section “
Configuring
Navigation Rules
”
on page
161
.
The
immediate
attribute of the
bookstore:map
tag is set to
true
, which indicates
that the default
javax.faces.event.ActionListener
implementation should
execute during the Apply Request Values phase of the request-processing lifecycle, in-
stead of waiting for the Invoke Application phase. Because the request resulting from
clicking the map does not require any validation, data conversion, or server-side object
updates, it makes sense to skip directly to the Invoke Application phase.
The
current
attribute of the
bookstore:map
tag is set to the default area, which is
map1
(the topic
My Early Years: Growing Up on Star7
, by Duke).
Notice that the
bookstore:area
tags do not contain any of the JavaScript, coordinate,
or shape data that is displayed on the HTML page. The JavaScript is generated by the
dukesbookstore.renderers.AreaRenderer
class. The
onmouseover
and
onmouseout
attribute values indicate the image to be loaded when these events occur.
How the JavaScript is generated is explained more in “
Performing Encoding
”
on page
The coordinate, shape, and alternate text data are obtained through the
value
attribute,
whose value refers to an attribute in application scope. The value of this attribute is a bean,
which stores the
coords
,
shape
, and
alt
data. How these beans are stored in the ap-
plication scope is explained more in the next section.
