NuxeoExceptionInterceptor.java

/*
 * (C) Copyright 2006-2009 Nuxeo SA (http://nuxeo.com/) and contributors.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public License
 * (LGPL) version 2.1 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * Contributors:
 *     Thierry Delprat
 */
package org.nuxeo.ecm.platform.ui.web.util;

import java.util.Map;

import javax.faces.event.PhaseId;

import org.jboss.seam.Component;
import org.jboss.seam.annotations.intercept.Interceptor;
import org.jboss.seam.contexts.FacesLifecycle;
import org.jboss.seam.faces.FacesMessages;
import org.jboss.seam.intercept.AbstractInterceptor;
import org.jboss.seam.intercept.InvocationContext;
import org.jboss.seam.international.StatusMessage.Severity;
import org.nuxeo.ecm.core.api.RecoverableClientException;
import org.nuxeo.ecm.platform.web.common.exceptionhandling.ExceptionHelper;

/**
 * Intercepts Seam Bean call during the INVOKE_APPLICATION phase to see if a
 * {@link RecoverableClientException} is raised. If this is the case, the INVOKE
 * call returns null and the associated FacesMessage is generated.
 * 
 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a>
 * @since 5.6
 */
@Interceptor
public class NuxeoExceptionInterceptor extends AbstractInterceptor {

    private static final long serialVersionUID = 1L;

    protected PhaseId getPhase() {
        return FacesLifecycle.getPhaseId();
    }

    protected Severity getSeverity(RecoverableClientException ce) {
        if (ce.getSeverity() == RecoverableClientException.Severity.WARN) {
            return Severity.WARN;
        } else if (ce.getSeverity() == RecoverableClientException.Severity.FATAL) {
            return Severity.FATAL;
        }
        return Severity.ERROR;
    }

    protected String getI18nMessage(String messageKey) {
        @SuppressWarnings("unchecked")
        Map<String, String> messages = (Map<String, String>) Component.getInstance(
                "org.jboss.seam.international.messages", true);

        if (messages == null) {
            return messageKey;
        }
        String i18nMessage = messages.get(messageKey);
        if (i18nMessage != null) {
            return i18nMessage;
        } else {
            return messageKey;
        }
    }

    @Override
    public Object aroundInvoke(InvocationContext invocationContext)
            throws Exception {
        try {
            return invocationContext.proceed();
        } catch (Exception t) {
            RecoverableClientException ce = null;
            if (t instanceof RecoverableClientException) {
                ce = (RecoverableClientException) t;
            } else {
                Throwable unwrappedException = ExceptionHelper.unwrapException(t);
                if (unwrappedException instanceof RecoverableClientException) {
                    ce = (RecoverableClientException) unwrappedException;
                }
            }
            if (ce != null) {
                Severity severity = getSeverity(ce);
                FacesMessages.instance().add(severity,
                        getI18nMessage(ce.getLocalizedMessage()),
                        (Object[]) ce.geLocalizedMessageParams());
                return null;
            }
            throw t;
        }
    }

    @Override
    public boolean isInterceptorEnabled() {
        PhaseId phase = getPhase();
        if (phase == null) {
            return true;
        }
        if (phase.equals(PhaseId.INVOKE_APPLICATION)) {
            return true;
        }

        return false;
    }

}