/*
* $Id: HtmlTag.java 664560 2008-06-08 21:32:02Z pbenedict $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.struts.taglib.html;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.Globals;
import org.apache.struts.taglib.TagUtils;
import org.apache.struts.util.MessageResources;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
import java.math.BigDecimal;
import java.util.Locale;
/**
* Renders an HTML <html> element with appropriate language attributes if
* there is a current Locale available in the user's session.
*
* @version $Rev: 664560 $ $Date: 2005-08-21 19:08:45 -0400 (Sun, 21 Aug 2005)
* $
*/
public class HtmlTag extends TagSupport {
// ------------------------------------------------------------- Properties
/**
* Commons Logging instance.
*/
private static Log log = LogFactory.getLog(HtmlTag.class);
/**
* The message resources for this package.
*/
protected static MessageResources messages =
MessageResources.getMessageResources(Constants.Package
+ ".LocalStrings");
/**
* Are we rendering an xhtml page?
*/
protected boolean xhtml = false;
/**
* What version of XHTML is being rendered?
*
* @since Struts 1.4
*/
private BigDecimal xhtmlVersion = TagUtils.XHTML_1_0;
/**
* Are we rendering a lang attribute?
*
* @since Struts 1.2
*/
protected boolean lang = false;
public boolean getXhtml() {
return this.xhtml;
}
public void setXhtml(boolean xhtml) {
this.xhtml = xhtml;
}
public String getXhtmlVersion() {
return this.xhtmlVersion.toString();
}
public void setXhtmlVersion(String xhtmlVersion) {
if (xhtmlVersion != null) {
this.xhtmlVersion = new BigDecimal(xhtmlVersion);
} else {
this.xhtmlVersion = TagUtils.XHTML_1_0;
}
}
/**
* Returns true if the tag should render a lang attribute.
*
* @since Struts 1.2
*/
public boolean getLang() {
return this.lang;
}
/**
* Sets whether the tag should render a lang attribute.
*
* @since Struts 1.2
*/
public void setLang(boolean lang) {
this.lang = lang;
}
/**
* Process the start of this tag.
*
* @throws JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
TagUtils.getInstance().write(this.pageContext,
this.renderHtmlStartElement());
return EVAL_BODY_INCLUDE;
}
/**
* Renders an <html> element with appropriate language attributes.
*
* @since Struts 1.2
*/
protected String renderHtmlStartElement() {
StringBuffer sb = new StringBuffer("<html");
String language = null;
String country = "";
Locale currentLocale =
TagUtils.getInstance().getUserLocale(pageContext, Globals.LOCALE_KEY);
language = currentLocale.getLanguage();
country = currentLocale.getCountry();
boolean validLanguage = isValidRfc2616(language);
boolean validCountry = isValidRfc2616(country);
// XHTML document conformance
if (this.xhtml) {
this.pageContext.setAttribute(Globals.XHTML_KEY, "true",
PageContext.PAGE_SCOPE);
this.pageContext.setAttribute(Globals.XHTML_VERSION_KEY,
xhtmlVersion, PageContext.REQUEST_SCOPE);
// 1.1
if (xhtmlVersion.equals(TagUtils.XHTML_1_1)) {
sb.append(" xmlns=\"http://www.w3.org/1999/xhtml\"");
sb.append(" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"");
sb.append(" xsi:schemaLocation=\"http://www.w3.org/MarkUp/SCHEMA/xhtml11.xsd\"");
}
// 2.0
else if (xhtmlVersion.equals(TagUtils.XHTML_2_0)) {
sb.append(" xmlns=\"http://www.w3.org/2002/06/xhtml2/\"");
sb.append(" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"");
sb.append(" xsi:schemaLocation=\"http://www.w3.org/2002/06/xhtml2/ http://www.w3.org/MarkUp/SCHEMA/xhtml2.xsd\"");
}
// 5.0
else if (xhtmlVersion.equals(TagUtils.XHTML_5_0)) {
sb.append(" xmlns=\"http://www.w3.org/1999/xhtml\"");
}
// 1.0/Default
else {
if (!xhtmlVersion.equals(TagUtils.XHTML_1_0)) {
log.warn("Defaulting to XHTML 1.0. Unknown version: " + xhtmlVersion);
xhtmlVersion = TagUtils.XHTML_1_0;
}
sb.append(" xmlns=\"http://www.w3.org/1999/xhtml\"");
}
}
// If language is specified, output the attribute
// unless XHTML is version >= 1.1
if (this.lang && validLanguage) {
if (!this.xhtml || (xhtmlVersion.compareTo(TagUtils.XHTML_1_1) < 0)) {
sb.append(" lang=\"");
sb.append(language);
if (validCountry) {
sb.append("-");
sb.append(country);
}
sb.append("\"");
}
}
if (this.xhtml && validLanguage) {
sb.append(" xml:lang=\"");
sb.append(language);
if (validCountry) {
sb.append("-");
sb.append(country);
}
sb.append("\"");
}
sb.append(">");
return sb.toString();
}
/**
* Process the end of this tag.
*
* @throws JspException if a JSP exception has occurred
*/
public int doEndTag() throws JspException {
TagUtils.getInstance().write(pageContext, "</html>");
// Evaluate the remainder of this page
return (EVAL_PAGE);
}
/**
* Release any acquired resources.
*/
public void release() {
this.xhtml = false;
this.lang = false;
}
/**
* Check whether the value contains valid characters for the
* "Accept-Language" header according to RFC 2616 (section 14.4).
*
* @param value The value to check
* @return <code>true</code> if valid, otherwise <code>false</code>
*/
private boolean isValidRfc2616(String value) {
if (value == null || value.length() == 0) {
return false;
}
for (int i = 0; i < value.length(); i++) {
char c = value.charAt(i);
if (!(Character.isLetter(c) || c == '-')) {
return false;
}
}
return true;
}
}