/** * Copyright (c) 2003-2005, David A. Czarnecki * All rights reserved. * * Portions Copyright (c) 2003-2005 by Mark Lussier * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the "David A. Czarnecki" and "blojsom" nor the names of * its contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * Products derived from this software may not be called "blojsom", * nor may "blojsom" appear in their name, without prior written permission of * David A. Czarnecki. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO * EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package org.blojsom.plugin.highlight; import org.blojsom.blog.BlogEntry; import org.blojsom.blog.BlogUser; import org.blojsom.blog.BlojsomConfiguration; import org.blojsom.plugin.BlojsomPlugin; import org.blojsom.plugin.BlojsomPluginException; import javax.servlet.ServletConfig; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.util.Map; import java.util.StringTokenizer; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * The GoogleHighlightPlugin will highlight words on your blog if the referer came from a Google * query. * <p/> * Based on work from http://www.textism.com/ * * @author Mark Lussier * @version $Id: GoogleHighlightPlugin.java,v 1.2.2.1 2005/07/21 04:30:31 johnan Exp $ */ public class GoogleHighlightPlugin implements BlojsomPlugin { /** * HTTP Header for Referer Information */ private static final String HEADER_REFERER = "referer"; private static final String START_BOUNDRY = "(\\b"; private static final String END_BOUNDRY = "\\b)"; /** * Expression used to identify the referer as a Google referer */ private static final String EXPRESSSION_GOOGLE = "^http:\\/\\/w?w?w?\\.?google.*"; private static final String EXPRESSION_HTMLPREFIX = "(?<=>)([^<]+)?"; private static final String EXPRESSION_HASTAGS = "<.+>"; /** * Expression used to extract the Query string portion of the referer */ private static final String GOOGLE_QUERY = "^.*q=([^&]+)&?.*$"; /** * Expression used to clean quotes */ private static final String GOOGLE_CLEANQUOTES = "'/\'|\"/\""; /** * Used to replace matches in entries that DO NOT have html tags */ private static final String HIGHLIGHT_PLAINTEXT = "<span class=\"searchhighlight\">$1</span>"; /** * Used to replace matches in entries that HAVE html tags */ private static final String HIGHLIGHT_HTML = "$1<span class=\"searchhighlight\">$2</span>"; /** * Initialize this plugin. This method only called when the plugin is instantiated. * * @param servletConfig Servlet config object for the plugin to retrieve any initialization parameters * @param blojsomConfiguration {@link org.blojsom.blog.BlojsomConfiguration} information * @throws BlojsomPluginException If there is an error initializing the plugin */ public void init(ServletConfig servletConfig, BlojsomConfiguration blojsomConfiguration) throws BlojsomPluginException { } /** * Extract search tokens from the Google Query String * * @param referer The Google referer * @return A string array of search words or <code>null</code> if no search query match is found */ private String[] extractQueryTokens(String referer) { String[] result = null; Matcher matcher = Pattern.compile(GOOGLE_QUERY, Pattern.CASE_INSENSITIVE).matcher(referer); if (matcher.find()) { String _query = matcher.group(1); _query = _query.replaceAll(GOOGLE_CLEANQUOTES, ""); StringTokenizer _st = new StringTokenizer(_query, "+, .", false); result = new String[_st.countTokens()]; int cnt = 0; while (_st.hasMoreElements()) { result[cnt] = _st.nextToken(); cnt += 1; } } return result; } /** * Process the blog entries * * @param httpServletRequest Request * @param httpServletResponse Response * @param user {@link BlogUser} instance * @param context Context * @param entries Blog entries retrieved for the particular request * @return Modified set of blog entries * @throws BlojsomPluginException If there is an error processing the blog entries */ public BlogEntry[] process(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlogUser user, Map context, BlogEntry[] entries) throws BlojsomPluginException { String referer = httpServletRequest.getHeader(HEADER_REFERER); if (referer != null && referer.matches(EXPRESSSION_GOOGLE)) { String[] searchwords = extractQueryTokens(referer); if (searchwords != null) { Pattern hasTags = Pattern.compile(EXPRESSION_HASTAGS); for (int x = 0; x < entries.length; x++) { BlogEntry entry = entries[x]; Matcher matcher = hasTags.matcher(entry.getDescription()); boolean isHtml = matcher.find(); for (int y = 0; y < searchwords.length; y++) { String word = searchwords[y]; if (!isHtml) { entry.setDescription(entry.getDescription().replaceAll(START_BOUNDRY + word + END_BOUNDRY, HIGHLIGHT_PLAINTEXT)); } else { entry.setDescription(entry.getDescription().replaceAll(EXPRESSION_HTMLPREFIX + START_BOUNDRY + word + END_BOUNDRY, HIGHLIGHT_HTML)); } } } } } return entries; } /** * Perform any cleanup for the plugin. Called after {@link #process}. * * @throws BlojsomPluginException If there is an error performing cleanup for this plugin */ public void cleanup() throws BlojsomPluginException { } /** * Called when BlojsomServlet is taken out of service * * @throws BlojsomPluginException If there is an error in finalizing this plugin */ public void destroy() throws BlojsomPluginException { } }