com.sun.faces.facelets.util.FunctionLibrary Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jakarta.faces-api Show documentation

Jakarta Faces defines an MVC framework for building user interfaces for web applications, including UI components, state management, event handing, input validation, page navigation, and support for internationalization and accessibility.

There is a newer version: 4.1.2

Show newest version

/*
 * Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package com.sun.faces.facelets.util;

import static com.sun.faces.util.Util.unmodifiableSet;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import com.sun.faces.facelets.tag.TagLibrary;
import com.sun.faces.util.Util;

import jakarta.faces.FacesException;
import jakarta.faces.view.facelets.Tag;
import jakarta.faces.view.facelets.TagConfig;
import jakarta.faces.view.facelets.TagHandler;

/**
 * 
 * This TagLibrary exposes the public static methods defined on the
 * functionsClass provided to the constructor as EL functions.
 * 
 */
public class FunctionLibrary implements TagLibrary {

    private final static String SunNamespace = "http://java.sun.com/jsp/jstl/functions";
    private final static String JcpNamespace = "http://xmlns.jcp.org/jsp/jstl/functions";
    private final static String JakartaNamespace = "jakarta.tags.functions";

    public final static Set NAMESPACES = unmodifiableSet(JakartaNamespace, JcpNamespace, SunNamespace);
    public final static String DEFAULT_NAMESPACE = JakartaNamespace;

    private String _namespace;
    private Map functions;

    // ------------------------------------------------------------ Constructors

    public FunctionLibrary(Class functionsClass, String namespace) {

        Util.notNull("functionsClass", functionsClass);
        Util.notNull("namespace", namespace);

        _namespace = namespace;

        try {
            Method[] methods = functionsClass.getMethods();
            functions = new HashMap<>(methods.length, 1.0f);
            for (Method method : methods) {
                if (Modifier.isStatic(method.getModifiers()) && Modifier.isPublic(method.getModifiers())) {
                    functions.put(method.getName(), method);
                }
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }

    // ------------------------------------------------- Methods from TagLibrary

    @Override
    public boolean containsNamespace(String ns, Tag t) {
        return _namespace.equals(ns);
    }

    @Override
    public boolean containsTagHandler(String ns, String localName) {
        return false;
    }

    @Override
    public TagHandler createTagHandler(String ns, String localName, TagConfig tag) throws FacesException {
        return null;
    }

    @Override
    public boolean containsFunction(String ns, String name) {
        return _namespace.equals(ns) && functions.containsKey(name);
    }

    @Override
    public Method createFunction(String ns, String name) {
        if (_namespace.equals(ns)) {
            return functions.get(name);
        }
        return null;
    }

}