org.cast.cwm.data.behavior.AjaxAutoSavingBehavior.java Source code

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Here is the source code for org.cast.cwm.data.behavior.AjaxAutoSavingBehavior.java

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/*
 * Copyright 2011-2016 CAST, Inc.
 *
 * This file is part of the CAST Wicket Modules:
 * see <http://code.google.com/p/cast-wicket-modules>.
 *
 * The CAST Wicket Modules are free software: you can redistribute and/or
 * modify them under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * The CAST Wicket Modules are distributed in the hope that they will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this software.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.cast.cwm.data.behavior;

import org.apache.wicket.AttributeModifier;
import org.apache.wicket.Component;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.form.AjaxFormSubmitBehavior;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.markup.head.JavaScriptHeaderItem;
import org.apache.wicket.markup.head.OnDomReadyHeaderItem;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.resource.PackageResourceReference;

/**
 * This behavior will submit a form at regular intervals.  Any HTML element
 * with class='autosave_info' will display the status of these automatic
 * saves.
 * 
 * @author jbrookover
 *
 */
public class AjaxAutoSavingBehavior extends AjaxFormSubmitBehavior {

    private static final long serialVersionUID = 1L;

    private static long updateInterval = 30000;

    private static final String AUTOSAVE_EVENT = "autosave";

    public static final PackageResourceReference AUTOSAVING_JAVASCRIPT = new PackageResourceReference(
            AjaxAutoSavingBehavior.class, "AjaxAutoSavingBehavior.js");

    /**
     * Constructor - attach to a component INSIDE the form.
     */
    public AjaxAutoSavingBehavior() {
        super(AUTOSAVE_EVENT);
        init();
    }

    /**
     * Constructor - attach to a component outside the form
     * or the form itself.
     * 
     * @param form
     */
    public AjaxAutoSavingBehavior(Form<?> form) {
        super(form, AUTOSAVE_EVENT);
        init();
    }

    /**
     * Initialize the Autosave behavior for this form.
     */
    protected void init() {
        getForm().setOutputMarkupId(true);
        getForm().add(AttributeModifier.append("class", "ajaxAutoSave"));
    }

    @Override
    protected void onError(AjaxRequestTarget target) {

    }

    @Override
    protected void onComponentTag(ComponentTag tag) {
        // This behavior is not triggered by an event; skip super.onComponentTag() to prevent writing javascript.
    }

    @Override
    protected final void onSubmit(AjaxRequestTarget target) {
        if (RequestCycle.get().getRequest().getRequestParameters().getParameterValue("autosave").toBoolean()) {
            onAutoSave(target);
        } else {
            throw new IllegalStateException("Autosaving request expected parameter autosave='true'");
        }
    }

    @Override
    public void renderHead(Component component, final IHeaderResponse response) {
        super.renderHead(component, response);

        // Run once to initialize
        response.render(JavaScriptHeaderItem.forReference(AUTOSAVING_JAVASCRIPT));
        response.render(JavaScriptHeaderItem.forScript("AutoSaver.setup(" + updateInterval + ");",
                "AjaxAutoSavingBehaviorSetup"));

        response.render(OnDomReadyHeaderItem.forScript("AutoSaver.makeLinksSafe();"));

        // Run each time to register this Form's default values and call-back URL with the AutoSaver
        response.render(OnDomReadyHeaderItem.forScript(
                "AutoSaver.addForm('" + getForm().getMarkupId() + "', '" + this.getCallbackUrl() + "');"));
    }

    /**
     * Called when the form auto-submits itself.  By default, this does nothing and presumes
     * the form should process silently in the background.  Override this method to provide
     * additional ajax changes to the page.
     * 
     * @param target
     */
    protected void onAutoSave(AjaxRequestTarget target) {

    }

    /**
     * Set the AutoSaving update interval for this application, in milliseconds.  Default
     * is every 30 seconds.
     * 
     * @param milliseconds
     */
    public static void setUpdateInterval(long milliseconds) {
        updateInterval = milliseconds;
    }

    /**
     * Get the AutoSaving update interval for this application, in milliseconds.
     * 
     * @return the interval, in milliseconds.
     */
    public static long getUpdateInterval() {
        return updateInterval;
    }

}