Java tutorial
/* * See the NOTICE file distributed with this work for additional * information regarding copyright ownership. * * This 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 software 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. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.xwiki.gwt.wysiwyg.client.plugin.submit; import org.xwiki.gwt.dom.client.DOMUtils; import org.xwiki.gwt.dom.client.Element; import org.xwiki.gwt.dom.client.JavaScriptObject; import org.xwiki.gwt.user.client.Config; import org.xwiki.gwt.user.client.StringUtils; import org.xwiki.gwt.user.client.ui.HiddenConfig; import org.xwiki.gwt.user.client.ui.rta.RichTextArea; import org.xwiki.gwt.user.client.ui.rta.cmd.Command; import org.xwiki.gwt.user.client.ui.rta.cmd.CommandListener; import org.xwiki.gwt.user.client.ui.rta.cmd.CommandManager; import org.xwiki.gwt.wysiwyg.client.plugin.internal.AbstractPlugin; import org.xwiki.gwt.wysiwyg.client.plugin.internal.StatelessUIExtension; import org.xwiki.gwt.wysiwyg.client.plugin.submit.exec.SubmitExecutable; import com.google.gwt.core.client.Scheduler; import com.google.gwt.core.client.Scheduler.ScheduledCommand; import com.google.gwt.dom.client.Document; import com.google.gwt.event.dom.client.BlurEvent; import com.google.gwt.event.dom.client.BlurHandler; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.Window.ClosingEvent; import com.google.gwt.user.client.Window.ClosingHandler; /** * Binds a {@link RichTextArea} to a form field. * * @version $Id: 5f0f366c86e0dfb266225f9be22ae50f9f72a4ff $ */ public class SubmitPlugin extends AbstractPlugin implements BlurHandler, CommandListener, ClosingHandler { /** * The name attribute, used by HTML form elements to pass data to the server when the form is submitted. */ private static final String NAME_ATTRIBUTE = "name"; /** * The name of the syntax configuration parameter. */ private static final String SYNTAX = "syntax"; /** * Default syntax. Can be overwritten from the configuration. */ private static final String DEFAULT_SYNTAX = "xhtml/1.0"; /** * The command used to store the value of the rich text area before submitting the including form. */ private static final Command SUBMIT = new Command("submit"); /** * This flag tells the server that it needs to convert the editor output from HTML to the storage syntax before * processing it. */ private static final String REQUIRES_HTML_CONVERSION = "RequiresHTMLConversion"; /** * The JavaScript object that catches the submit event and calls {@link #onSubmit()}. We couldn't use a FormPanel * because it overwrites the onsubmit property of the form element instead of registering itself as a listener. */ private JavaScriptObject submitHandler; /** * Extends the root of the editor UI. Examples of similar root extensions are the tool bar and the menu bar. */ private final StatelessUIExtension rootExtension = new StatelessUIExtension("root"); /** * Additional data to be sent to the server, besides the content of the rich text area. */ private HiddenConfig hiddenConfig; /** * The HTML form that contains the rich text area. */ private Element form; @Override public void init(RichTextArea textArea, Config config) { super.init(textArea, config); String hookId = getConfig().getParameter("hookId"); getTextArea().getCommandManager().registerCommand(SUBMIT, new SubmitExecutable(textArea, hookId)); if (getTextArea().getCommandManager().isSupported(SUBMIT)) { Element hook = (Element) Document.get().getElementById(hookId); // See if the hook is inside an HTML form. form = (Element) DOMUtils.getInstance().getFirstAncestor(hook, "form"); // We don't use hook.hasAttribute because the name attribute appears as unspecified in IE if it has been set // from JavaScript. if (form != null && !StringUtils.isEmpty(hook.getAttribute(NAME_ATTRIBUTE))) { // Put additional hidden data on the HTML form. hiddenConfig = new HiddenConfig(); // All the parameters of this hidden configuration will be prefixed with the name of the hook. hiddenConfig.setNameSpace(hook.getAttribute(NAME_ATTRIBUTE)); // This flag tells the server that the editor output requires HTML conversion. if (textArea.isEnabled()) { hiddenConfig.addFlag(REQUIRES_HTML_CONVERSION); } // The storage syntax for this rich text area. hiddenConfig.setParameter(SYNTAX, config.getParameter(SYNTAX, DEFAULT_SYNTAX)); rootExtension.addFeature(SUBMIT.toString(), hiddenConfig); getUIExtensionList().add(rootExtension); // Listen to submit event. hookSubmitEvent(form); } // Save the initial content of the rich text area, after all the plug-ins have been initialized. // Note that we can't use the "loaded" action event because event handlers are registered after the current // event is processed. In this case the "loaded" action event is fired after all the plug-ins have been // initialized but still while the rich text area "load" event is handled (and the reason for this is to // ensure the order of the action events). Scheduler.get().scheduleDeferred(new ScheduledCommand() { public void execute() { onSubmit(); } }); // Submit the content when the rich text area looses the focus or the user navigates away. saveRegistration(getTextArea().addBlurHandler(this)); saveRegistration(Window.addWindowClosingHandler(this)); // Prevent the rich text area from being submitted when it is disabled. getTextArea().getCommandManager().addCommandListener(this); } } @Override public void destroy() { if (rootExtension.getFeatures().length > 0) { unhookSubmitEvent(form); form = null; hiddenConfig.removeFromParent(); hiddenConfig = null; submitHandler = null; rootExtension.clearFeatures(); } getTextArea().getCommandManager().removeCommandListener(this); super.destroy(); } /** * @return the JavaScript object that catches the submit event and calls {@link #onSubmit()} */ protected native JavaScriptObject getSubmitHandler() /*-{ if (!this.@org.xwiki.gwt.wysiwyg.client.plugin.submit.SubmitPlugin::submitHandler) { var _this = this; this.@org.xwiki.gwt.wysiwyg.client.plugin.submit.SubmitPlugin::submitHandler = function() { _this.@org.xwiki.gwt.wysiwyg.client.plugin.submit.SubmitPlugin::onSubmit()(); }; } return this.@org.xwiki.gwt.wysiwyg.client.plugin.submit.SubmitPlugin::submitHandler; }-*/; /** * Registers {@link #getSubmitHandler()} as a listener for submit events generated by the given HTML form element. * * @param form the HTML form element whose submit event should be listened */ protected native void hookSubmitEvent(Element form) /*-{ var handler = this.@org.xwiki.gwt.wysiwyg.client.plugin.submit.SubmitPlugin::getSubmitHandler()(); form.addEventListener('submit', handler, false); }-*/; /** * Unregisters {@link #getSubmitHandler()} as a listener for submit events generated by the given HTML form element. * * @param form the HTML form element whose submit event shouldn't be listened anymore */ protected native void unhookSubmitEvent(Element form) /*-{ var handler = this.@org.xwiki.gwt.wysiwyg.client.plugin.submit.SubmitPlugin::getSubmitHandler()(); form.removeEventListener('submit', handler, false); }-*/; @Override public void onBlur(BlurEvent event) { if (event.getSource() == getTextArea()) { onSubmit(); } } /** * Called when the HTML form hosting the rich text area is submitted. */ protected void onSubmit() { // Submit the content of the rich text area only if it is enabled. if (getTextArea().isAttached() && getTextArea().isEnabled()) { getTextArea().getCommandManager().execute(SUBMIT); } } @Override public boolean onBeforeCommand(CommandManager sender, Command command, String param) { // ignore return false; } @Override public void onCommand(CommandManager sender, Command command, String param) { if (hiddenConfig != null && sender == getTextArea().getCommandManager() && Command.ENABLE.equals(command)) { if (getTextArea().getCommandManager().isExecuted(Command.ENABLE)) { hiddenConfig.addFlag(REQUIRES_HTML_CONVERSION); } else { hiddenConfig.removeFlag(REQUIRES_HTML_CONVERSION); } } } @Override public void onWindowClosing(ClosingEvent event) { // Allow the browser to cache the content of the rich text area when the user navigates away from the edit page. onSubmit(); } }