001/*
002 * (C) Copyright 2006-2015 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 *     Nuxeo - initial API and implementation
016 *
017 * $Id$
018 */
019
020package org.nuxeo.ecm.platform.preview.adapter;
021
022import java.io.IOException;
023import java.io.UnsupportedEncodingException;
024import java.util.ArrayList;
025import java.util.List;
026
027import org.apache.commons.lang.StringUtils;
028import org.nuxeo.ecm.core.api.Blob;
029import org.nuxeo.ecm.core.api.Blobs;
030import org.nuxeo.ecm.core.api.DocumentModel;
031import org.nuxeo.ecm.platform.preview.api.PreviewException;
032
033import com.ibm.icu.text.CharsetDetector;
034
035public class PlainTextPreviewer extends AbstractPreviewer implements MimeTypePreviewer {
036
037    public String htmlContent(String content) {
038        // & and < are the only two that we really need to escape
039        // then we also make newlines visible
040        String escaped = StringUtils.replaceEach(content, //
041                new String[] { "&", "<", "\n" }, //
042                new String[] { "&amp;", "&lt;", "<br/>" });
043        return "<pre>" + escaped + "</pre>";
044    }
045
046    @Override
047    public List<Blob> getPreview(Blob blob, DocumentModel dm) throws PreviewException {
048        List<Blob> blobResults = new ArrayList<Blob>();
049
050        StringBuilder htmlPage = new StringBuilder();
051
052        byte[] data;
053        try {
054            data = blob.getByteArray();
055        } catch (IOException e) {
056            throw new PreviewException("Cannot fetch blob content", e);
057        }
058        String encoding = blob.getEncoding();
059        if (StringUtils.isEmpty(encoding)) {
060            CharsetDetector detector = new CharsetDetector();
061            detector.setText(data);
062            encoding = detector.detect().getName();
063        }
064
065        String content = null;
066        try {
067            content = new String(data, encoding);
068        } catch (UnsupportedEncodingException e) {
069            throw new PreviewException("Cannot encode blob content to string", e);
070        }
071
072        htmlPage.append("<?xml version=\"1.0\" encoding=\"UTF-8\"/>");
073        htmlPage.append("<html>");
074        htmlPage.append("<head><meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/></head>");
075        htmlPage.append("<body>");
076        htmlPage.append(htmlContent(content));
077        htmlPage.append("</body></html>");
078
079        Blob mainBlob = Blobs.createBlob(htmlPage.toString(), "text/html", "UTF-8", "index.html");
080
081        blobResults.add(mainBlob);
082        return blobResults;
083    }
084
085}