001/*
002 * (C) Copyright 2006-2008 Nuxeo SAS (http://nuxeo.com/) and contributors.
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the GNU Lesser General Public License
006 * (LGPL) version 2.1 which accompanies this distribution, and is available at
007 * http://www.gnu.org/licenses/lgpl.html
008 *
009 * This library is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * Contributors:
015 *     Alexandre Russel
016 *
017 * $Id$
018 */
019
020package org.nuxeo.ecm.diff.content.adapter;
021
022import java.io.IOException;
023import java.io.StringWriter;
024import java.util.ArrayList;
025import java.util.List;
026import java.util.Locale;
027
028import javax.xml.transform.TransformerConfigurationException;
029import javax.xml.transform.TransformerFactory;
030import javax.xml.transform.sax.SAXTransformerFactory;
031import javax.xml.transform.sax.TransformerHandler;
032import javax.xml.transform.stream.StreamResult;
033
034import org.apache.commons.lang.StringUtils;
035import org.apache.commons.logging.Log;
036import org.apache.commons.logging.LogFactory;
037import org.nuxeo.ecm.core.api.Blob;
038import org.nuxeo.ecm.core.api.Blobs;
039import org.nuxeo.ecm.core.api.DocumentModel;
040import org.nuxeo.ecm.core.api.blobholder.BlobHolder;
041import org.nuxeo.ecm.diff.content.ContentDiffException;
042import org.nuxeo.ecm.diff.content.ContentDiffHelper;
043import org.nuxeo.ecm.platform.web.common.vh.VirtualHostHelper;
044import org.outerj.daisy.diff.HtmlCleaner;
045import org.outerj.daisy.diff.XslFilter;
046import org.outerj.daisy.diff.html.HTMLDiffer;
047import org.outerj.daisy.diff.html.HtmlSaxDiffOutput;
048import org.outerj.daisy.diff.html.TextNodeComparator;
049import org.outerj.daisy.diff.html.dom.DomTreeBuilder;
050import org.xml.sax.ContentHandler;
051import org.xml.sax.InputSource;
052import org.xml.sax.SAXException;
053import org.xml.sax.helpers.AttributesImpl;
054
055/**
056 * @author Antoine Taillefer
057 * @since 5.6
058 */
059public class HtmlContentDiffer implements MimeTypeContentDiffer {
060
061    private static final Log LOGGER = LogFactory.getLog(HtmlContentDiffer.class);
062
063    protected static final String NUXEO_DEFAULT_CONTEXT_PATH = "/nuxeo";
064
065    @Override
066    public List<Blob> getContentDiff(DocumentModel leftDoc, DocumentModel rightDoc, String xpath, Locale locale)
067            throws ContentDiffException {
068        Blob leftBlob = null;
069        Blob rightBlob = null;
070        BlobHolder leftBlobHolder = null;
071        BlobHolder rightBlobHolder = null;
072        if (StringUtils.isBlank(xpath) || ContentDiffHelper.DEFAULT_XPATH.equals(xpath)) {
073            leftBlobHolder = leftDoc.getAdapter(BlobHolder.class);
074            rightBlobHolder = rightDoc.getAdapter(BlobHolder.class);
075        } else {
076            leftBlobHolder = ContentDiffHelper.getBlobHolder(leftDoc, xpath);
077            rightBlobHolder = ContentDiffHelper.getBlobHolder(rightDoc, xpath);
078        }
079        if (leftBlobHolder == null || rightBlobHolder == null) {
080            throw new ContentDiffException("Can not make a content diff of documents without a blob");
081        }
082        leftBlob = leftBlobHolder.getBlob();
083        rightBlob = rightBlobHolder.getBlob();
084        if (leftBlob == null || rightBlob == null) {
085            throw new ContentDiffException("Can not make a content diff of documents without a blob");
086        }
087        return getContentDiff(leftBlob, rightBlob, locale);
088    }
089
090    @Override
091    public List<Blob> getContentDiff(Blob leftBlob, Blob rightBlob, Locale locale) throws ContentDiffException {
092
093        try {
094            List<Blob> blobResults = new ArrayList<Blob>();
095            StringWriter sw = new StringWriter();
096
097            SAXTransformerFactory stf = (SAXTransformerFactory) TransformerFactory.newInstance();
098            TransformerHandler transformHandler = stf.newTransformerHandler();
099            transformHandler.setResult(new StreamResult(sw));
100
101            XslFilter htmlHeaderXslFilter = new XslFilter();
102
103            StringBuilder sb = new StringBuilder("xslfilter/htmldiffheader");
104            sb.append("_");
105            sb.append(locale.getLanguage());
106            sb.append(".xsl");
107            String htmlHeaderXslPath = sb.toString();
108            ContentHandler postProcess;
109            try {
110                postProcess = htmlHeaderXslFilter.xsl(transformHandler, htmlHeaderXslPath);
111            } catch (IllegalStateException ise) {
112                LOGGER.error(String.format(
113                        "Could not find the HTML diff header xsl file '%s', falling back on the default one.",
114                        htmlHeaderXslPath), ise);
115                postProcess = htmlHeaderXslFilter.xsl(transformHandler, "xslfilter/htmldiffheader.xsl");
116            }
117
118            String prefix = "diff";
119
120            HtmlCleaner cleaner = new HtmlCleaner();
121
122            InputSource leftIS = new InputSource(leftBlob.getStream());
123            InputSource rightIS = new InputSource(rightBlob.getStream());
124
125            DomTreeBuilder leftHandler = new DomTreeBuilder();
126            cleaner.cleanAndParse(leftIS, leftHandler);
127            TextNodeComparator leftComparator = new TextNodeComparator(leftHandler, locale);
128
129            DomTreeBuilder rightHandler = new DomTreeBuilder();
130            cleaner.cleanAndParse(rightIS, rightHandler);
131            TextNodeComparator rightComparator = new TextNodeComparator(rightHandler, locale);
132
133            postProcess.startDocument();
134            postProcess.startElement("", "diffreport", "diffreport", new AttributesImpl());
135            postProcess.startElement("", "diff", "diff", new AttributesImpl());
136            HtmlSaxDiffOutput output = new HtmlSaxDiffOutput(postProcess, prefix);
137
138            HTMLDiffer differ = new HTMLDiffer(output);
139            differ.diff(leftComparator, rightComparator);
140
141            postProcess.endElement("", "diff", "diff");
142            postProcess.endElement("", "diffreport", "diffreport");
143            postProcess.endDocument();
144
145            String stringBlob = sw.toString().replaceAll(NUXEO_DEFAULT_CONTEXT_PATH,
146                    VirtualHostHelper.getContextPathProperty());
147            Blob mainBlob = Blobs.createBlob(stringBlob);
148            sw.close();
149
150            mainBlob.setFilename("contentDiff.html");
151            mainBlob.setMimeType("text/html");
152
153            blobResults.add(mainBlob);
154            return blobResults;
155
156        } catch (TransformerConfigurationException | SAXException | IOException e) {
157            throw new ContentDiffException(e);
158        }
159    }
160}