definitionloaders.java

ZK 基础介绍 功能操作 模块 结合数据库操作

/* DefinitionLoaders.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Mon Aug 29 21:57:08     2005, Created by tomyeh
}}IS_NOTE

Copyright (C) 2005 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.ui.metainfo;

import java.lang.reflect.Field;
import java.util.Iterator;
import java.util.ListIterator;
import java.util.List;
import java.util.LinkedList;
import java.util.Set;
import java.util.HashSet;
import java.util.Map;
import java.util.HashMap;
import java.util.Enumeration;
import java.net.URL;
import java.io.IOException;

import org.zkoss.lang.D;
import org.zkoss.lang.Classes;
import org.zkoss.lang.Strings;
import org.zkoss.util.Utils;
import org.zkoss.util.logging.Log;
import org.zkoss.util.resource.Locator;
import org.zkoss.util.resource.ClassLocator;
import org.zkoss.idom.Document;
import org.zkoss.idom.Element;
import org.zkoss.idom.Attribute;
import org.zkoss.idom.ProcessingInstruction;
import org.zkoss.idom.input.SAXBuilder;
import org.zkoss.idom.util.IDOMs;
import org.zkoss.xel.taglib.Taglib;
import org.zkoss.web.servlet.JavaScript;
import org.zkoss.web.servlet.StyleSheet;

import org.zkoss.zk.Version;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.metainfo.impl.*;
import org.zkoss.zk.scripting.Interpreters;
import org.zkoss.zk.device.Devices;

/**
 * Utilities to load language definitions.
 *
 * @author tomyeh
 */
public class DefinitionLoaders {
	private static final Log log = Log.lookup(DefinitionLoaders.class);

	private static final int MAX_VERSION_SEGMENT = 4;
	private static List _addons;
	/** A map of (String ext, String lang). */
	private static Map _exts;
	private static boolean _loaded, _loading;

	//CONSIDER:
	//Sotre language definitions per WebApp, since diff app may add its
	//own definitions thru WEB-INF's lang-addon, or a JAR in WEB-INF/lib.
	//
	//CONSEQUENCE:
	//Other Web app is affected by another in the current implementation
	//
	//WORKAROUND:
	//Copy ZK libraries into WEB-INF/lib
	//
	//DIFFICULTY TO SUPPORT
	//To support it we have to pass WebApp around. It is a challenge for
	//1) a working thread (other than servlet/event thread);
	//2) deserialize LanguageDefinition (and maybe ComponentDefinition)

	/** Adds a language addon.
	 */
	public static void addAddon(Locator locator, URL url) {
		if (locator == null || url == null)
			throw new IllegalArgumentException("null");

		if (_loaded) {
			loadAddon(locator, url);
		} else {
			if (_addons == null)
				_addons = new LinkedList();
			_addons.add(new Object[] {locator, url});
		}
	}
	/** Associates an extension to a language.
	 *
	 * @param lang the language name. It cannot be null.
	 * @param ext the extension, e.g., "svg". It cannot be null.
	 * @since 3.0.0
	 */
	public static final void addExtension(String ext, String lang) {
		if (_loaded) {
			LanguageDefinition.addExtension(ext, lang);
		} else {
			if (lang == null || ext == null)
				throw new IllegalArgumentException("null");
			if (_exts == null)
				_exts = new HashMap();
			_exts.put(ext, lang);
		}
	}

	/** Loads all config.xml, lang.xml and lang-addon.xml found in
	 * the /metainfo/zk path.
	 *
	 * <p>Remember to call {@link #addAddon}, if necessary, before
	 * calling this method.
	 */
	/*package*/ static void load() {
		if (!_loaded) {
			synchronized (DefinitionLoaders.class) {
				if (!_loaded && !_loading) {
					try {
						_loading = true; //prevent re-entry for the same thread
						load0();
					} finally {
						_loaded = true; //only once
						_loading = false;
					}
				}
			}
		}
	}
	private static void load0() {
		final ClassLocator locator = new ClassLocator();

		final int[] zkver = new int[MAX_VERSION_SEGMENT];
		for (int j = 0; j < MAX_VERSION_SEGMENT; ++j)
			zkver[j] = Utils.getSubversion(Version.UID, j);

		//1. process config.xml (no particular dependency)
		try {
			final List xmls = locator.getDependentXMLResources(
				"metainfo/zk/config.xml", "config-name", "depends");
			for (Iterator it = xmls.iterator(); it.hasNext();) {
				final ClassLocator.Resource res = (ClassLocator.Resource)it.next();
				if (log.debugable()) log.debug("Loading "+res.url);
				try {
					if (checkVersion(zkver, res.url, res.document))
						parseConfig(res.document.getRootElement());
				} catch (Exception ex) {
					throw UiException.Aide.wrap(ex, "Failed to load "+res.url);
						//abort since it is hardly to work then
				}
			}
		} catch (Exception ex) {
			throw UiException.Aide.wrap(ex); //abort
		}

		//2. process lang.xml (no particular dependency)
		try {
			for (Enumeration en = locator.getResources("metainfo/zk/lang.xml");
			en.hasMoreElements();) {
				final URL url = (URL)en.nextElement();
				if (log.debugable()) log.debug("Loading "+url);
				try {
					final Document doc = new SAXBuilder(false, false, true).build(url);
					if (checkVersion(zkver, url, doc))
						parseLang(doc, locator, false);
				} catch (Exception ex) {
					throw UiException.Aide.wrap(ex, "Failed to load "+url);
						//abort since it is hardly to work then
				}
			}
		} catch (Exception ex) {
			throw UiException.Aide.wrap(ex); //abort
		}

		//3. process lang-addon.xml (with dependency)
		try {
			final List xmls = locator.getDependentXMLResources(
				"metainfo/zk/lang-addon.xml", "addon-name", "depends");
			for (Iterator it = xmls.iterator(); it.hasNext();) {
				final ClassLocator.Resource res = (ClassLocator.Resource)it.next();
				try {
					if (checkVersion(zkver, res.url, res.document))
						parseLang(res.document, locator, true);
				} catch (Exception ex) {
					log.error("Failed to load addon", ex);
					//keep running
				}
			}
		} catch (Exception ex) {
			log.error("Failed to load addon", ex);
			//keep running
		}

		//4. process other addon (from addAddon)
		if (_addons != null) {
			for (Iterator it = _addons.iterator(); it.hasNext();) {
				final Object[] p = (Object[])it.next();
				loadAddon((Locator)p[0], (URL)p[1]);
			}
			_addons = null; //free memory
		}

		//5. process the extension
		if (_exts != null) {
			for (Iterator it = _exts.entrySet().iterator(); it.hasNext();) {
				final Map.Entry me = (Map.Entry)it.next();
				LanguageDefinition.addExtension((String)me.getKey(),
					(String)me.getValue());
			}
			_exts = null;
		}
	}
	/** Loads a language addon.
	 */
	private static void loadAddon(Locator locator, URL url) {
		try {
			parseLang(
				new SAXBuilder(false, false, true).build(url), locator, true);
		} catch (Exception ex) {
			log.error("Failed to load addon: "+url, ex);
			//keep running
		}
	}

	/** Checks and returns whether the loaded document's version is correct.
	 */
	private static boolean checkVersion(int[] zkver, URL url, Document doc)
	throws Exception {
		final Element el = doc.getRootElement().getElement("version");
		if (el != null) {
			final String reqzkver = el.getElementValue("zk-version", true);
			if (reqzkver != null) {
				for (int j = 0; j < MAX_VERSION_SEGMENT; ++j) {
					int v = Utils.getSubversion(reqzkver, j);
					if (v < zkver[j]) break; //ok
					if (v > zkver[j]) {//failed
						log.info("Ignore "+url+"\nCause: ZK version must be "+zkver+" or later, not "+Version.UID);
						return false;
					}
				}
			}

			final String clsnm = IDOMs.getRequiredElementValue(el, "version-class");
			final String uid = IDOMs.getRequiredElementValue(el, "version-uid");
			final Class cls = Classes.forNameByThread(clsnm);
			final Field fld = cls.getField("UID");
			final String uidInClass = (String)fld.get(null);
			if (uid.equals(uidInClass)) {
				return true;
			} else {
				log.info("Ignore "+url+"\nCause: version not matched; expected="+uidInClass+", xml="+uid);
				return false;
			}
		} else {
			log.info("Ignore "+url+"\nCause: version not specified");
			return false; //backward compatible
		}
	}

	private static void parseConfig(Element el)
	throws Exception {
		parseZScriptConfig(el);
		parseDeviceConfig(el);
	}
	private static void parseZScriptConfig(Element root) {
		for (Iterator it = root.getElements("zscript-config").iterator();
		it.hasNext();) {
			final Element el = (Element)it.next();
			Interpreters.add(el);
				//Note: zscript-config is applied to the whole system, not just langdef
		}
	}
	private static void parseDeviceConfig(Element root) {
		for (Iterator it = root.getElements("device-config").iterator();
		it.hasNext();) {
			final Element el = (Element)it.next();
			Devices.add(el);
		}
	}

	private static void parseLang(Document doc, Locator locator, boolean addon)
	throws Exception {
		final Element root = doc.getRootElement();
		final String lang = IDOMs.getRequiredElementValue(root, "language-name");
		final LanguageDefinition langdef;
		if (addon) {
			if (log.debugable()) log.debug("Addon language to "+lang+" from "+root.getElementValue("addon-name", true));
			langdef = LanguageDefinition.lookup(lang);

			if (root.getElement("case-insensitive") != null)
				throw new UiException("case-insensitive not allowed in addon");
		} else {
			final String ns =
				(String)IDOMs.getRequiredElementValue(root, "namespace");
			final String deviceType =
				(String)IDOMs.getRequiredElementValue(root, "device-type");

			//if (log.debugable()) log.debug("Load language: "+lang+", "+ns);

			final Map pagemolds = parseMolds(root);
			final String desktopURI = (String)pagemolds.get("desktop");
			final String pageURI = (String)pagemolds.get("page");
			if (desktopURI == null || pageURI == null)
				throw new UiException("Both desktop and page molds must be specified, "+root.getLocator());
			if (desktopURI.startsWith("class:") || pageURI.startsWith("class:"))
				throw new UiException("Both desktop and page molds don't support 'class:', "+root.getLocator());