dsp:getvalueof lets you save a JavaBean component, Page parameter, or Static value to an attribute in the specified scope. Other tags such as dsp:valueof can then reference that value. The attribute is also accessible to the JSP Expression Language (EL).
dsp:getvalueof has the following syntax:
<dsp:getvalueofsource-valuevar="var-name" [scope="scope-spec"] ] > </getvalueof>
where source-value specifies the value sources as a JavaBean component, Page parameter, or Static value:
bean="nucleus-path/component-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 attribute student to reference the Nucleus component /atg/samples/Student_01. The tag omits a scope specification, so the default pageScope is applied:
<dsp:getvalueof bean="/atg/samples/Student_01" var="student"></dsp:getvalueof>
The attribute student 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="${student.age}"/> years old.
Page parameter
dsp:getvalueof can make page parameters available to EL. For example, given the page parameter sex, dsp:getvalueof can set the requestScope attribute gender to reference that parameter:
<dsp:getvalueof param="sex" var="gender" scope="request"> </dsp:getvalueof>
After you set this attribute, it is accessible to other objects in the same request scope. In the following example, the c:when tag evaluates requestScope.gender in order to determine which content to display:
<c:choose>
<c:when test="${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 attribute resolve to the literal string student.
