dsp:getvalueof lets you save a JavaBean component, Page parameter, or Static value to a variable in the specified scope. Other tags such as dsp:valueof
can then reference that value. The variable is also accessible to the JSP Expression Language.
dsp:getvalueof
has the following syntax:
<dsp:getvalueofsource-value
var="var-name
" [scope="scope-spec
"] ] > </getvalueof>
where source-value
specifies the value source as a JavaBean component, Page parameter, or Static value:
bean="
nucleus-path/c
omponent
-name
"
param="
param-name
"
value="
static-value
"
JavaBean component
dsp:getvalueof
can make JavaBean components available to EL. The following dsp:getvalueof
tag sets the student
variable to the Nucleus component /atg/samples/Student_01
. The tag omits the scope
attribute, so the default pageScope
is applied:
<dsp:getvalueof bean="/atg/samples/Student_01" var="student"></dsp:getvalueof>
The student
variable provides access on the current JSP to all Student_01
component properties. For example, you can use EL to render this component’s age
property:
You are <c:out value="${student.age}"/> years old.
Page parameter
dsp:getvalueof
can make page parameters available to EL. In the next example, dsp:getvalueof
sets the requestScope
variable gender
to reference the page parameter sex
:
<dsp:getvalueof param="sex" var="gender" scope="request"> </dsp:getvalueof>
After you set this variable, it is accessible to other objects in the same request scope. In the following example, the c:when
tag evaluates requestScope.gender
in order to determine which content to display:
<c:choose> <c:when test="${gender == "female"}"/> Formal dresses are on sale! </c:when> <c:when test="${gender == "male"}"> Tuxedos are on sale! <c:when> </c:choose>
Static value
dsp:getvalueof
can save a static value to an EL variable, as in the following example:
<dsp:getvalueof value="student" var="userType"> </dsp:getvalueof>
Subsequent references to the userType
variable resolve to the literal string student
.