/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.anodyneos.xp.tag.fmt;
import java.util.Enumeration;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.el.ELException;
import org.anodyneos.xp.XpContext;
import org.anodyneos.xp.XpException;
import org.anodyneos.xp.XpOutput;
import org.anodyneos.xp.http.HttpXpContext;
import org.anodyneos.xp.tag.Config;
import org.anodyneos.xp.tag.Util;
import org.anodyneos.xp.tagext.XpTagSupport;
import org.xml.sax.SAXException;
/**
* Support for tag handlers for <bundle>, the resource bundle loading tag
* in JSTL 1.0.
*
* @author jvas
*/
public class BundleTag extends XpTagSupport {
// *********************************************************************
// Private constants
private static final Locale EMPTY_LOCALE = new Locale("", "");
// *********************************************************************
// Protected state
protected String basename; // 'basename' attribute
protected String prefix; // 'prefix' attribute
// *********************************************************************
// Private state
private Locale fallbackLocale;
private LocalizationContext locCtxt;
// *********************************************************************
// Constructor and initialization
// tag attribute
public void setBasename(String basename) {
this.basename = basename;
}
// tag attribute
public void setPrefix(String prefix) {
this.prefix = prefix;
}
// *********************************************************************
// Collaboration with subtags
public LocalizationContext getLocalizationContext() {
return locCtxt;
}
public String getPrefix() {
return prefix;
}
// *********************************************************************
// Tag logic
public void doTag(XpOutput out) throws XpException, ELException, SAXException {
locCtxt = getLocalizationContext(((XpContext) getXpContext()), basename);
getXpBody().invoke(out);
}
// *********************************************************************
// Public utility methods
/**
* Gets the default I18N localization context.
*
* @param pc
* Page in which to look up the default I18N localization context
*/
public static LocalizationContext getLocalizationContext(XpContext pc) {
LocalizationContext locCtxt = null;
Object obj = Config.find(pc, Config.FMT_LOCALIZATION_CONTEXT);
if (obj == null) {
return null;
}
if (obj instanceof LocalizationContext) {
locCtxt = (LocalizationContext) obj;
} else {
// localization context is a bundle basename
locCtxt = getLocalizationContext(pc, (String) obj);
}
return locCtxt;
}
/**
* Gets the resource bundle with the given base name, whose locale is
* determined as follows:
*
* Check if a match exists between the ordered set of preferred locales and
* the available locales, for the given base name. The set of preferred
* locales consists of a single locale (if the
* <tt>javax.servlet.jsp.jstl.fmt.locale</tt> configuration setting is
* present) or is equal to the client's preferred locales determined from
* the client's browser settings.
*
* <p>
* If no match was found in the previous step, check if a match exists
* between the fallback locale (given by the
* <tt>javax.servlet.jsp.jstl.fmt.fallbackLocale</tt> configuration
* setting) and the available locales, for the given base name.
*
* @param pageContext
* Page in which the resource bundle with the given base name is
* requested
* @param basename
* Resource bundle base name
*
* @return Localization context containing the resource bundle with the
* given base name and the locale that led to the resource bundle
* match, or the empty localization context if no resource bundle
* match was found
*/
public static LocalizationContext getLocalizationContext(XpContext pc, String basename) {
LocalizationContext locCtxt = null;
ResourceBundle bundle = null;
if ((basename == null) || basename.equals("")) {
return new LocalizationContext();
}
// Try preferred locales
Locale pref = SetLocaleTag.getLocale(pc, Config.FMT_LOCALE);
if (pref != null) {
// Preferred locale is application-based
bundle = findMatch(basename, pref);
if (bundle != null) {
locCtxt = new LocalizationContext(bundle, pref);
}
} else {
// Preferred locales are browser-based
locCtxt = findMatch(pc, basename);
}
if (locCtxt == null) {
// No match found with preferred locales, try using fallback locale
pref = SetLocaleTag.getLocale(pc, Config.FMT_FALLBACK_LOCALE);
if (pref != null) {
bundle = findMatch(basename, pref);
if (bundle != null) {
locCtxt = new LocalizationContext(bundle, pref);
}
}
}
if (locCtxt == null) {
// try using the root resource bundle with the given basename
try {
bundle = ResourceBundle.getBundle(basename, EMPTY_LOCALE, Thread.currentThread()
.getContextClassLoader());
if (bundle != null) {
locCtxt = new LocalizationContext(bundle, null);
}
} catch (MissingResourceException mre) {
// do nothing
}
}
if (locCtxt != null) {
// set response locale
// Not done for XP since charset is set with <xp:output>
// if (locCtxt.getLocale() != null) {
// SetLocaleSupport.setResponseLocale(pc, locCtxt.getLocale());
// }
} else {
// create empty localization context
locCtxt = new LocalizationContext();
}
return locCtxt;
}
// *********************************************************************
// Private utility methods
/*
* Determines the client's preferred locales from the request, and compares
* each of the locales (in order of preference) against the available
* locales in order to determine the best matching locale.
*
* @param pageContext the page in which the resource bundle with the given
* base name is requested @param basename the resource bundle's base name
*
* @return the localization context containing the resource bundle with the
* given base name and best matching locale, or <tt> null </tt> if no
* resource bundle match was found
*/
private static LocalizationContext findMatch(XpContext xpc, String basename) {
if (! (xpc instanceof HttpXpContext)) {
// We don't know what the client wants.
return null;
} else {
// Determine locale from client's browser settings.
HttpXpContext hxpc = (HttpXpContext) xpc;
LocalizationContext locCtxt = null;
for (Enumeration enum_ = Util.getRequestLocales((HttpServletRequest) hxpc.getRequest()); enum_
.hasMoreElements();) {
Locale pref = (Locale) enum_.nextElement();
ResourceBundle match = findMatch(basename, pref);
if (match != null) {
locCtxt = new LocalizationContext(match, pref);
break;
}
}
return locCtxt;
}
}
/*
* Gets the resource bundle with the given base name and preferred locale.
*
* This method calls java.util.ResourceBundle.getBundle(), but ignores its
* return value unless its locale represents an exact or language match with
* the given preferred locale.
*
* @param basename the resource bundle base name @param pref the preferred
* locale
*
* @return the requested resource bundle, or <tt> null </tt> if no resource
* bundle with the given base name exists or if there is no exact- or
* language-match between the preferred locale and the locale of the bundle
* returned by java.util.ResourceBundle.getBundle().
*/
private static ResourceBundle findMatch(String basename, Locale pref) {
ResourceBundle match = null;
try {
ResourceBundle bundle = ResourceBundle.getBundle(basename, pref, Thread.currentThread()
.getContextClassLoader());
Locale avail = bundle.getLocale();
if (pref.equals(avail)) {
// Exact match
match = bundle;
} else {
/*
* We have to make sure that the match we got is for the
* specified locale. The way ResourceBundle.getBundle() works,
* if a match is not found with (1) the specified locale, it
* tries to match with (2) the current default locale as
* returned by Locale.getDefault() or (3) the root resource
* bundle (basename). We must ignore any match that could have
* worked with (2) or (3). So if an exact match is not found, we
* make the following extra tests: - avail locale must be equal
* to preferred locale - avail country must be empty or equal to
* preferred country (the equality match might have failed on
* the variant)
*/
if (pref.getLanguage().equals(avail.getLanguage())
&& ("".equals(avail.getCountry()) || pref.getCountry().equals(avail.getCountry()))) {
/*
* Language match. By making sure the available locale does
* not have a country and matches the preferred locale's
* language, we rule out "matches" based on the container's
* default locale. For example, if the preferred locale is
* "en-US", the container's default locale is "en-UK", and
* there is a resource bundle (with the requested base name)
* available for "en-UK", ResourceBundle.getBundle() will
* return it, but even though its language matches that of
* the preferred locale, we must ignore it, because matches
* based on the container's default locale are not portable
* across different containers with different default
* locales.
*/
match = bundle;
}
}
} catch (MissingResourceException mre) {
}
return match;
}
}