/*
* Copyright 2010 Google Inc.
*
* 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 com.google.gwt.i18n.linker;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.linker.ConfigurationProperty;
import com.google.gwt.core.ext.linker.PropertyProviderGenerator;
import com.google.gwt.user.rebind.SourceWriter;
import com.google.gwt.user.rebind.StringSourceWriter;
import java.util.SortedSet;
import java.util.regex.Pattern;
/**
* Generates a property provider implementation for the "locale" property.
*/
public class LocalePropertyProviderGenerator implements PropertyProviderGenerator {
public static final String LOCALE_QUERYPARAM = "locale.queryparam";
public static final String LOCALE_COOKIE = "locale.cookie";
public static final String LOCALE_SEARCHORDER = "locale.searchorder";
public static final String LOCALE_USEMETA = "locale.usemeta";
public static final String LOCALE_USERAGENT = "locale.useragent";
protected static final Pattern COOKIE_PATTERN = Pattern.compile("^[A-Za-z][A-Za-z0-9_]*$");
protected static final Pattern QUERYPARAM_PATTERN = Pattern.compile("^[A-Za-z][A-Za-z0-9_]*$");
/**
* Return true when the supplied value represents a true/yes/on value.
*
* @param value
* @return true if the string represents true/yes/on
*/
protected static boolean isTrue(String value) {
return value != null && ("yes".equalsIgnoreCase(value)
|| "y".equalsIgnoreCase(value) || "true".equalsIgnoreCase(value)
|| "on".equalsIgnoreCase(value));
}
public String generate(TreeLogger logger, SortedSet<String> possibleValues,
String fallback, SortedSet<ConfigurationProperty> configProperties)
throws UnableToCompleteException {
// get relevant config property values
String localeQueryParam = null;
String localeCookie = null;
boolean localeUserAgent = false;
boolean localeUseMeta = false;
String localeSearchOrder = "queryparam,cookie,meta,useragent";
for (ConfigurationProperty configProp : configProperties) {
String name = configProp.getName();
if (LOCALE_QUERYPARAM.equals(name)) {
localeQueryParam = configProp.getValues().get(0);
if (localeQueryParam != null && localeQueryParam.length() != 0
&& !validateQueryParam(localeQueryParam)) {
logger.log(TreeLogger.WARN, "Ignoring invalid value of '"
+ localeQueryParam + "' from '" + LOCALE_QUERYPARAM
+ "', not a valid query parameter name");
localeQueryParam = null;
}
} else if (LOCALE_COOKIE.equals(name)) {
localeCookie = configProp.getValues().get(0);
if (localeCookie != null && localeCookie.length() != 0
&& !validateCookieName(localeCookie)) {
logger.log(TreeLogger.WARN, "Ignoring invalid value of '"
+ localeCookie + "' from '" + LOCALE_COOKIE
+ "', not a valid cookie name");
localeCookie = null;
}
} else if (LOCALE_USEMETA.equals(name)) {
localeUseMeta = isTrue(configProp.getValues().get(0));
} else if (LOCALE_USERAGENT.equals(name)) {
localeUserAgent = isTrue(configProp.getValues().get(0));
} else if (LOCALE_SEARCHORDER.equals(name)) {
localeSearchOrder = configProp.getValues().get(0);
}
}
// provide a default for the search order
localeSearchOrder = localeSearchOrder.trim();
if (localeSearchOrder == null || localeSearchOrder.length() == 0) {
localeSearchOrder = "queryparam,cookie,meta,useragent";
}
if (fallback == null) {
// TODO(jat): define this in a common place
fallback = "default";
}
// build property provider body
StringSourceWriter body = new StringSourceWriter();
body.println("{");
body.indent();
body.println("var locale = null;");
body.println("var rtlocale = '" + fallback + "';");
body.println("try {");
for (String method : localeSearchOrder.split(",")) {
if ("queryparam".equals(method)) {
if (localeQueryParam != null && localeQueryParam.length() > 0) {
body.println("if (!locale) {");
body.indent();
generateQueryParamLookup(logger, body, localeQueryParam);
body.outdent();
body.println("}");
}
} else if ("cookie".equals(method)) {
if (localeCookie != null && localeCookie.length() > 0) {
body.println("if (!locale) {");
body.indent();
generateCookieLookup(logger, body, localeCookie);
body.outdent();
body.println("}");
}
} else if ("meta".equals(method)) {
if (localeUseMeta) {
body.println("if (!locale) {");
body.indent();
generateMetaLookup(logger, body);
body.outdent();
body.println("}");
}
} else if ("useragent".equals(method)) {
if (localeUserAgent) {
body.println("if (!locale) {");
body.indent();
generateUserAgentLookup(logger, body);
body.outdent();
body.println("}");
}
} else {
logger.log(TreeLogger.WARN, "Ignoring unknown locale lookup method \""
+ method + "\"");
body.println("// ignoring invalid lookup method '" + method + "'");
}
}
body.println("if (!locale) {");
body.indent();
body.println("locale = $wnd['__gwt_Locale'];");
body.outdent();
body.println("}");
body.println("if (locale) {");
body.indent();
body.println("rtlocale = locale;");
body.outdent();
body.println("}");
generateInheritanceLookup(logger, body);
body.outdent();
body.println("} catch (e) {");
body.indent();
body.println("alert(\"Unexpected exception in locale detection, using "
+ "default: \" + e);\n");
body.outdent();
body.println("}");
body.println("$wnd['__gwt_Locale'] = rtlocale;");
body.println("return locale || \"" + fallback + "\";");
body.outdent();
body.println("}");
return body.toString();
}
/**
* Generate JS code that looks up the locale value from a cookie.
*
* @param logger logger to use
* @param body
* @param cookieName
* @throws UnableToCompleteException
*/
protected void generateCookieLookup(TreeLogger logger, SourceWriter body,
String cookieName) throws UnableToCompleteException {
body.println("var cookies = $doc.cookie;");
body.println("var idx = cookies.indexOf(\"" + cookieName + "=\");");
body.println("if (idx >= 0) {");
body.indent();
body.println("var end = cookies.indexOf(';', idx);");
body.println("if (end < 0) {");
body.indent();
body.println("end = cookies.length;");
body.outdent();
body.println("}");
body.println("locale = cookies.substring(idx + " + (cookieName.length() + 1)
+ ", end);");
body.outdent();
body.println("}");
}
/**
* Generate JS code that takes the value of the "locale" variable and finds
* parent locales until the value is a supported locale or the default locale.
*
* @param logger logger to use
* @param body
* @throws UnableToCompleteException
*/
protected void generateInheritanceLookup(TreeLogger logger, SourceWriter body)
throws UnableToCompleteException {
body.println("while (locale && !__gwt_isKnownPropertyValue(\"locale\", locale)) {");
body.indent();
body.println("var lastIndex = locale.lastIndexOf(\"_\");");
body.println("if (lastIndex < 0) {");
body.indent();
body.println("locale = null;");
body.println("break;");
body.outdent();
body.println("}");
body.println("locale = locale.substring(0, lastIndex);");
body.outdent();
body.println("}");
}
/**
* Generate JS code to fetch the locale from a meta property.
*
* @param logger logger to use
* @param body
* @throws UnableToCompleteException
*/
protected void generateMetaLookup(TreeLogger logger, SourceWriter body)
throws UnableToCompleteException {
// TODO(jat): do we want to allow customizing the meta property name?
body.println("locale = __gwt_getMetaProperty(\"locale\");");
}
/**
* Generate JS code to get the locale from a query parameter.
*
* @param logger logger to use
* @param body where to append JS output
* @param queryParam the query parameter to use
* @throws UnableToCompleteException
*/
protected void generateQueryParamLookup(TreeLogger logger, SourceWriter body,
String queryParam) throws UnableToCompleteException {
body.println("var queryParam = location.search;");
body.println("var qpStart = queryParam.indexOf(\"" + queryParam + "=\");");
body.println("if (qpStart >= 0) {");
body.indent();
body.println("var value = queryParam.substring(qpStart + "
+ (queryParam.length() + 1) + ");");
body.println("var end = queryParam.indexOf(\"&\", qpStart);");
body.println("if (end < 0) {");
body.indent();
body.println("end = queryParam.length;");
body.outdent();
body.println("}");
body.println("locale = queryParam.substring(qpStart + "
+ (queryParam.length() + 1) + ", end);");
body.outdent();
body.println("}");
}
/**
* Generate JS code to fetch the locale from the user agent's compile-time
* locale.
*
* @param logger logger to use
* @param body
* @throws UnableToCompleteException
*/
protected void generateUserAgentLookup(TreeLogger logger, SourceWriter body)
throws UnableToCompleteException {
body.println("var language = navigator.browserLanguage ? "
+ "navigator.browserLanguage : navigator.language;");
body.println("if (language) {");
body.indent();
body.println("var parts = language.split(/[-_]/);");
body.println("if (parts.length > 1) {");
body.indent();
body.println("parts[1] = parts[1].toUpperCase();");
body.outdent();
body.println("}");
body.println("locale = parts.join(\"_\");");
body.outdent();
body.println("}");
}
/**
* Validate that a name is a valid cookie name.
*
* @param cookieName
* @return true if cookieName is an acceptable cookie name
*/
protected boolean validateCookieName(String cookieName) {
return COOKIE_PATTERN.matcher(cookieName).matches();
}
/**
* Validate that a value is a valid query parameter name.
*
* @param queryParam
* @return true if queryParam is a valid query parameter name.
*/
protected boolean validateQueryParam(String queryParam) {
return QUERYPARAM_PATTERN.matcher(queryParam).matches();
}
}