Question

Is it possible to overload an EL method in JSF 1.1 using Facelets as your view handler? If so, how?

For example, I have this code defining my EL methods (which are defined in namespace k):

public static String doStuff( String s ) {
    return doStuff( null, s );
}

public static String doStuff( Map<String,String> m, String s ) {
    ...
    return something;
}

When I try to call #{k:doStuff("hey!")} from my Facelets page, I get this error:

Function 'k:doStuff' specifies 2 params, but 1 was declared

Answer 1

It looks like the problem was with how it was declared. For example, I was using this to declare my methods:

public class KTagLib extends AbstractTagLibrary {
    public static final String NAMESPACE = "http://mysite.blah/tags";
    public static final KTagLib INSTANCE = new KTagLib();

    public KTagLib() {
        super(NAMESPACE);
        try{
            try {
                Method[] methods = KTags.class.getMethods();

                for (int i = 0; i < methods.length; i++) {
                    if (Modifier.isStatic(methods[i].getModifiers())) {
                        this.addFunction(methods[i].getName(), methods[i]);
                    }
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            }            
        }
    }

and using the following configuration:

<?xml version="1.0"?>
<!DOCTYPE facelet-taglib PUBLIC "-//Sun Microsystems, Inc.//DTD Facelet Taglib 1.0//EN" "http://java.sun.com/dtd/facelet-taglib_1_0.dtd">
<facelet-taglib>
    <library-class>mypackage.KTagLib</library-class>
</facelet-taglib>

However, the this.addFunction() is essentially calling put() on a java.util.Map object so that duplicate methods can’t be added since the keys are the same between doStuff.

To solve this problem, I’ll have to explicitly declare the methods in the *.taglib.xml unless anyone knows of a way to dynamically solve the problems.