All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.opencms.gwt.client.validation.CmsValidationScheduler Maven / Gradle / Ivy

Go to download

OpenCms is an enterprise-ready, easy to use website content management system based on Java and XML technology. Offering a complete set of features, OpenCms helps content managers worldwide to create and maintain beautiful websites fast and efficiently.

There is a newer version: 18.0
Show newest version
/*
 * This library is part of OpenCms -
 * the Open Source Content Management System
 *
 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * 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.
 *
 * For further information about Alkacon Software, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.gwt.client.validation;

import java.util.LinkedList;

/**
 * This is a helper class for scheduling form validations.

* * Since validations can be asynchronous, it would be possible for a validation to start while another one * is still waiting for a response from the server if it were ran directly. This might result in an inconsistent state * of the form fields being validated. To prevent this, validation controllers use this class to schedule validations, * and call this class again after they're finished to execute the next validation.

* * The result of this is that a validation will only start after all unfinished validations which have been scheduled * before it have finished running.

* * @since 8.0.0 */ public class CmsValidationScheduler { /** The singleton instance of this class. */ private static CmsValidationScheduler instance = new CmsValidationScheduler(); /** The queue of validations which still need to be run. */ private LinkedList m_actions = new LinkedList(); /** A flag which indicates whether there is no validation currently running. */ private boolean m_idle = true; /** * Hidden default constructor.

*/ protected CmsValidationScheduler() { // do nothing } /** * Returns the singleton instance of the validation scheduler.

* * @return the validation scheduler */ public static CmsValidationScheduler get() { return instance; } /** * This method should be called by the validation controller when it has finished running.

* * It will execute the next validation if there is one.

*/ public void executeNext() { if (!m_idle) { if (m_actions.isEmpty()) { m_idle = true; } else { CmsValidationController action = m_actions.removeFirst(); action.internalStartValidation(); } } else { assert false; // this shouldn't happen } } /** * This schedules a new validation to be run after all currently scheduled or running validations have finished.

* * If there are no validations running, the validation will be started immediately.

* * @param action the validation to be scheduled */ public void schedule(CmsValidationController action) { if (m_idle) { m_idle = false; action.internalStartValidation(); } else { m_actions.add(action); } } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy