device.java

ZK 基础介绍 功能操作 模块 结合数据库操作

/* Device.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Mon May 14 19:13:14     2007, Created by tomyeh
}}IS_NOTE

Copyright (C) 2007 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.device;

import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.sys.ServerPush;

/**
 * Represents a client device.
 * For example, the HTML browsers with Ajax are called {@link AjaxDevice},
 * the XML output called org.zkoss.zml.device.XmlDevice,
 * and the MIL device called org.zkoss.mil.device.MilDevice.
 *
 * <p>Note: the same device is shared by all desktops of the same device
 * type.
 *
 * @author tomyeh
 * @since 2.4.0
 */
public interface Device {
	/** Returns the device type.
	 */
	public String getType();

	/** Returns whether the output can be cached by the client.
	 */
	public boolean isCacheable();

	/** Returns the unavailable message that is shown to the client
	 * if the client doesn't support this device.
	 *
	 * @return the unavailable message, or null if no such message
	 * @since 2.4.0
	 */
	public String getUnavailableMessage();
	/** Sets the unavailable message that is shown to the client
	 * if the client doesn't support this device.
	 *
	 * @param unavailmsg the unavailable message.
	 * @return the previous unavailable message, or null if not such message
	 * @since 2.4.0
	 */
	public String setUnavailableMessage(String unavailmsg);

	/** Returns the timeout URI for this device.
	 * It is used to show the error message if the desktop being requested
	 * is not found. It is usually caused by session timeout.
	 *
	 * <p>Default: null (to shown an error message).
	 *
	 * @since 3.0.0
	 */
	public String getTimeoutURI();
	/** Sets the timeout URI.
	 * It is used to show the error message if the desktop being requested
	 * is not found. It is usually caused by session timeout.
	 *
	 * @param timeoutURI the timeout URI. If empty, it means to reload
	 * the same page. If null, an error message is shown instead of
	 * redirecting to another page.
	 * @return the previous timeout URI, or null if not available.
	 * @since 3.0.0
	 */
	public String setTimeoutURI(String timeoutURI);

	/** Returns the class that implements the server-push feature
	 * ({@link ServerPush}) for this device, or null if the default is used.
	 * @since 3.0.0
	 */
	public Class getServerPushClass();
	/** Sets the class that implements the server-push feature
	 * ({@link ServerPush}) for this device, or null to use the default.
	 *
	 * <p>Default: null.
	 *
	 * <p>If the professional edition (with zkex.jar) is loaded,
	 * the client-polling-based server push (org.zkoss.zkex.ui.impl.PollingServerPush)
	 * is the default.
	 * If the enterprise edition (with zkmax.jar) is loaded,
	 * the COMET-based server push (org.zkoss.zkmax.ui.impl.CometServerPush)
	 * is the default.
	 * @return the previous class, or null if not available.
	 * @since 3.0.0
	 */
	public Class setServerPushClass(Class cls);

	/** Returns the default content type (never null).
	 * 
	 * @since 3.0.0
	 */
	public String getContentType();
	/** Returns the default doc type, or null if no doc type at all.
	 *
	 * @since 3.0.0
	 */
	public String getDocType();

	/** Initializes the device.
	 * A device is created for each desktop, and this method is called
	 * when it is associated to the desktop.
	 *
	 * @param deviceType the device type (never null)
	 * @param config the configuration to initialize the device (never null)
	 * @since 3.0.0
	 */
	public void init(String deviceType, DeviceConfig config);
	/** Notification that the desktop, which owns this device,
	 * is about to be passivated (aka., serialized) by the Web container.
	 * @since 2.4.0
	 */
	public void sessionWillPassivate(Desktop desktop);
	/** Notification that the desktop, which owns this device,
	 * has just been activated (aka., deserialized) by the Web container.
	 * @since 2.4.0
	 */
	public void sessionDidActivate(Desktop desktop);
}