com.sun.faces.application.applicationimpl.ExpressionLanguage Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jakarta.faces Show documentation
EE4J Compatible Implementation for Jakarta Faces API
The newest version!
/*
 * Copyright (c) 2023 Contributors to Eclipse Foundation.
 * 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.application.applicationimpl;

import static com.sun.faces.util.MessageUtils.ILLEGAL_ATTEMPT_SETTING_APPLICATION_ARTIFACT_ID;
import static com.sun.faces.util.MessageUtils.getExceptionMessageString;
import static com.sun.faces.util.Util.getCdiBeanManager;

import com.sun.faces.application.ApplicationAssociate;
import com.sun.faces.el.FacesCompositeELResolver;
import jakarta.el.CompositeELResolver;
import jakarta.el.ELContextListener;
import jakarta.el.ELException;
import jakarta.el.ELResolver;
import jakarta.el.ExpressionFactory;
import jakarta.enterprise.inject.spi.el.ELAwareBeanManager;
import jakarta.faces.context.FacesContext;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

public class ExpressionLanguage {

    private static final ELContextListener[] EMPTY_EL_CTX_LIST_ARRAY = {};

    private final ApplicationAssociate associate;

    private final List elContextListeners;
    private final CompositeELResolver elResolvers;
    private volatile FacesCompositeELResolver compositeELResolver;

    public ExpressionLanguage(ApplicationAssociate applicationAssociate) {
        associate = applicationAssociate;
        elContextListeners = new CopyOnWriteArrayList<>();
        elResolvers = new CompositeELResolver();
    }

    /*
     * @see jakarta.faces.application.Application#addELContextListener(jakarta.el.ELContextListener)
     */
    public void addELContextListener(ELContextListener listener) {
        if (listener != null) {
            elContextListeners.add(listener);
        }
    }

    /*
     * @see jakarta.faces.application.Application#removeELContextListener(jakarta.el.ELContextListener)
     */
    public void removeELContextListener(ELContextListener listener) {
        if (listener != null) {
            elContextListeners.remove(listener);
        }
    }

    /*
     * @see jakarta.faces.application.Application#getELContextListeners()
     */
    public ELContextListener[] getELContextListeners() {
        if (!elContextListeners.isEmpty()) {
            return elContextListeners.toArray(new ELContextListener[elContextListeners.size()]);
        }

        return EMPTY_EL_CTX_LIST_ARRAY;
    }

    /*
     * @see jakarta.faces.application.Application#getELResolver()
     */
    public ELResolver getELResolver() {
        if (compositeELResolver == null) {
            synchronized (this) {
                if (compositeELResolver == null) {
                    performOneTimeELInitialization();
                }
            }
        }

        return compositeELResolver;
    }

    /*
     * @see jakarta.faces.application.Application#addELResolver(jakarta.el.ELResolver)
     */
    public void addELResolver(ELResolver resolver) {
        if (associate.hasRequestBeenServiced()) {
            throw new IllegalStateException(getExceptionMessageString(ILLEGAL_ATTEMPT_SETTING_APPLICATION_ARTIFACT_ID, "ELResolver"));
        }

        FacesContext facesContext = FacesContext.getCurrentInstance();
        ELAwareBeanManager cdiBeanManager = getCdiBeanManager(facesContext);

        if (!resolver.equals(cdiBeanManager.getELResolver())) {
            elResolvers.add(resolver);
        }
    }

    /*
     * @see jakarta.faces.application.Application#getExpressionFactory()
     */
    public ExpressionFactory getExpressionFactory() {
        return associate.getExpressionFactory();
    }

    /*
     * @see jakarta.faces.application.Application#evaluateExpressionGet(jakarta.faces.context.FacesContext, String, Class)
     */
    @SuppressWarnings("unchecked")
    public  T evaluateExpressionGet(FacesContext context, String expression, Class expectedType) throws ELException {
        return (T) getExpressionFactory().createValueExpression(context.getELContext(), expression, expectedType).getValue(context.getELContext());
    }

    public CompositeELResolver getApplicationELResolvers() {
        return elResolvers;
    }

    public FacesCompositeELResolver getCompositeELResolver() {
        return compositeELResolver;
    }

    public void setCompositeELResolver(FacesCompositeELResolver compositeELResolver) {
        this.compositeELResolver = compositeELResolver;
    }

    private void performOneTimeELInitialization() {
        if (compositeELResolver != null) {
            throw new IllegalStateException("Class invariant invalidated: " + "The Application instance's ELResolver is not null " + "and it should be.");
        }
        associate.initializeELResolverChains();
    }

}