/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* For further information about Alkacon Software GmbH, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import org.htmlparser.Parser;
import org.htmlparser.PrototypicalNodeFactory;
import org.htmlparser.Remark;
import org.htmlparser.Tag;
import org.htmlparser.Text;
import org.htmlparser.lexer.Lexer;
import org.htmlparser.lexer.Page;
import org.htmlparser.util.ParserException;
import org.htmlparser.visitors.NodeVisitor;
/**
* Base utility class for OpenCms <code>{@link org.htmlparser.visitors.NodeVisitor}</code>
* implementations, which provides some often used utility functions.
* <p>
*
* This base implementation is only a "pass through" class, that is the content is parsed, but the
* generated result is exactly identical to the input.
* <p>
*
* @since 6.2.0
*/
public class CmsHtmlParser extends NodeVisitor implements I_CmsHtmlNodeVisitor {
/** List of upper case tag name strings of tags that should not be auto-corrected if closing divs are missing. */
protected List<String> m_noAutoCloseTags;
/** The array of supported tag names. */
// important: don't change the order of these tags in the source, subclasses may expect the tags
// at the exact indices give here
// if you want to add tags, add them at the end
protected static final String[] TAG_ARRAY = new String[] {
"H1",
"H2",
"H3",
"H4",
"H5",
"H6",
"P",
"DIV",
"SPAN",
"BR",
"OL",
"UL",
"LI",
"TABLE",
"TD",
"TR",
"TH",
"THEAD",
"TBODY",
"TFOOT"};
/** The list of supported tag names. */
protected static final List<String> TAG_LIST = Arrays.asList(TAG_ARRAY);
/** Indicates if "echo" mode is on, that is all content is written to the result by default. */
protected boolean m_echo;
/** The buffer to write the out to. */
protected StringBuffer m_result;
/** The providable configuration - never null by contract of interface. */
private String m_configuration = "";
/**
* Creates a new instance of the html converter with echo mode set to <code>false</code>.
* <p>
*/
public CmsHtmlParser() {
this(false);
}
/**
* Creates a new instance of the html converter.
* <p>
*
* @param echo indicates if "echo" mode is on, that is all content is written to the result
*/
public CmsHtmlParser(boolean echo) {
m_result = new StringBuffer(1024);
m_echo = echo;
m_noAutoCloseTags = new ArrayList<String>(32);
}
/**
* Internally degrades Composite tags that do have children in the DOM tree
* to simple single tags. This allows to avoid auto correction of unclosed HTML tags.<p>
*
* @return A node factory that will not autocorrect open tags specified via <code>{@link #setNoAutoCloseTags(List)}</code>
*/
protected PrototypicalNodeFactory configureNoAutoCorrectionTags() {
PrototypicalNodeFactory factory = new PrototypicalNodeFactory();
String tagName;
Iterator<String> it = m_noAutoCloseTags.iterator();
CmsNoAutoCloseTag noAutoCloseTag;
while (it.hasNext()) {
tagName = it.next();
noAutoCloseTag = new CmsNoAutoCloseTag(new String[] {tagName});
// TODO: This might break in case registering / unregistering will change from name based to tag-type based approach:
factory.unregisterTag(noAutoCloseTag);
factory.registerTag(noAutoCloseTag);
}
return factory;
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#getConfiguration()
*/
public String getConfiguration() {
return m_configuration;
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#getResult()
*/
public String getResult() {
return m_result.toString();
}
/**
* Returns the HTML for the given tag itself (not the tag content).
* <p>
*
* @param tag the tag to create the HTML for
*
* @return the HTML for the given tag
*/
public String getTagHtml(Tag tag) {
StringBuffer result = new StringBuffer(32);
result.append('<');
result.append(tag.getText());
result.append('>');
return result.toString();
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#process(java.lang.String, java.lang.String)
*/
public String process(String html, String encoding) throws ParserException {
m_result = new StringBuffer();
Parser parser = new Parser();
Lexer lexer = new Lexer();
// initialize the page with the given char set
Page page = new Page(html, encoding);
lexer.setPage(page);
parser.setLexer(lexer);
if (m_noAutoCloseTags != null && m_noAutoCloseTags.size() > 0) {
// Degrade Composite tags that do have children in the DOM tree
// to simple single tags: This allows to finish this tag with opened HTML tags without the effect
// that html parser will generate the closing tags.
PrototypicalNodeFactory factory = configureNoAutoCorrectionTags();
lexer.setNodeFactory(factory);
}
// process the page using the given visitor
parser.visitAllNodesWith(this);
// return the result
return getResult();
}
/**
*
* @see org.opencms.util.I_CmsHtmlNodeVisitor#setConfiguration(java.lang.String)
*/
public void setConfiguration(String configuration) {
if (CmsStringUtil.isNotEmpty(configuration)) {
m_configuration = configuration;
}
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#visitEndTag(org.htmlparser.Tag)
*/
@Override
public void visitEndTag(Tag tag) {
if (m_echo) {
m_result.append(getTagHtml(tag));
}
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#visitRemarkNode(org.htmlparser.Remark)
*/
@Override
public void visitRemarkNode(Remark remark) {
if (m_echo) {
m_result.append(remark.toHtml(true));
}
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#visitStringNode(org.htmlparser.Text)
*/
@Override
public void visitStringNode(Text text) {
if (m_echo) {
m_result.append(text.getText());
}
}
/**
* @see org.opencms.util.I_CmsHtmlNodeVisitor#visitTag(org.htmlparser.Tag)
*/
@Override
public void visitTag(Tag tag) {
if (m_echo) {
m_result.append(getTagHtml(tag));
}
}
/**
* Collapse HTML whitespace in the given String.<p>
*
* @param string the string to collapse
*
* @return the input String with all HTML whitespace collapsed
*/
protected String collapse(String string) {
int len = string.length();
StringBuffer result = new StringBuffer(len);
int state = 0;
for (int i = 0; i < len; i++) {
char c = string.charAt(i);
switch (c) {
// see HTML specification section 9.1 White space
// http://www.w3.org/TR/html4/struct/text.html#h-9.1
case '\u0020':
case '\u0009':
case '\u000C':
case '\u200B':
case '\r':
case '\n':
if (0 != state) {
state = 1;
}
break;
default:
if (1 == state) {
result.append(' ');
}
state = 2;
result.append(c);
}
}
return result.toString();
}
/**
* Returns a list of upper case tag names for which parsing / visiting will not correct missing closing tags.<p>
*
* @return a List of upper case tag names for which parsing / visiting will not correct missing closing tags
*/
public List<String> getNoAutoCloseTags() {
return m_noAutoCloseTags;
}
/**
* Sets a list of upper case tag names for which parsing / visiting should not correct missing closing tags.<p>
*
* @param noAutoCloseTagList a list of upper case tag names for which parsing / visiting
* should not correct missing closing tags to set.
*/
public void setNoAutoCloseTags(List<String> noAutoCloseTagList) {
// ensuring upper case
m_noAutoCloseTags.clear();
if (noAutoCloseTagList != null) {
Iterator<String> it = noAutoCloseTagList.iterator();
while (it.hasNext()) {
m_noAutoCloseTags.add((it.next()).toUpperCase());
}
}
}
}