Passing array in an EL taglib function

[Allan Cheong]

Hi all,

I am playing with some codes and found that I am unable to create such function:

.tld

	<uri>CustomFunction</uri>
	<function>
		<name>test</name>
		<function-class>com.function.MyFunction</function-class>
		<function-signature>java.lang.String testFunction(java.lang.String, java.lang.String[])</function-signature>
	</function>

MyFunction.java

	public static String testFunction(String a, String ... b) {
	}

.jsp

<%@taglib prefix="cf" uri="CustomFunction" %>
${cf:testFunction("XXX", "1", "2", "3")}</br>

The problem occurs at .jsp I believe. However if I change the .jsp to the following, it works.

<%@taglib prefix="cf" uri="CustomFunction" %>
<% request.setAttribute("strings", new String[]{"100", "200", "300"}); %>
${cf:testFunction("XXX", strings)}

Any ideas on how I can pass array (String ...) in a taglib function in JSP?

[Ankit Garg]

As far as I remember this is not supported yet...

[Allan Cheong]

Noted with thanks.

[Frits Walraven]

Any ideas on how I can pass array (String ...) in a taglib function in JSP?

If variable arguments where supported you would have to define the function in the TLD like this:
<function-signature>java.lang.String testFunction(java.lang.String, java.lang.String...)</function-signature>
but that gives the following error:

The class java.lang.String... specified in the method signature in TLD for the function formTags:testFunction cannot be found.

It is expecting a fully qualified class name as parameter.

The proof can actually be found in the jsp2.0 specs:

JSP.C.1XML Schema for TLD, JSP 2.0
<xsd:element name="function-signature" type="j2ee:string">
<xsd:annotation>

<xsd:documentation>
Provides the signature, of the static Java method that is
to be used to implement the function. The syntax of the

function-signature element is as follows:

FunctionSignature ::= ReturnType S MethodName S? '(' S? Parameters? S? ')'
ReturnType ::= Type
MethodName ::= Identifier
Parameters ::= Parameter | ( Parameter S? ',' S? Parameters )
Parameter ::= Type
Where:
* Type is a basic type or a fully qualified Java class name (including package name), as per the 'Type' production in the Java Language Specification

Regards,
Frits