001/*
002 * (C) Copyright 2006-2018 Nuxeo (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 *
019 * $Id$
020 */
021
022package org.nuxeo.ecm.platform.preview.adapter;
023
024import java.io.IOException;
025import java.io.UnsupportedEncodingException;
026import java.util.ArrayList;
027import java.util.List;
028
029import org.apache.commons.lang3.StringUtils;
030import org.nuxeo.ecm.core.api.Blob;
031import org.nuxeo.ecm.core.api.Blobs;
032import org.nuxeo.ecm.core.api.DocumentModel;
033import org.nuxeo.ecm.platform.preview.api.PreviewException;
034import org.nuxeo.ecm.platform.preview.helper.PreviewHelper;
035
036import com.ibm.icu.text.CharsetDetector;
037
038public class PlainTextPreviewer extends AbstractPreviewer implements MimeTypePreviewer {
039
040    public String htmlContent(String content) {
041        // & and < are the only two that we really need to escape
042        // then we also make newlines visible
043        String escaped = StringUtils.replaceEach(content, //
044                new String[] { "&", "<", "\n" }, //
045                new String[] { "&amp;", "&lt;", "<br/>" });
046        return "<pre>" + escaped + "</pre>";
047    }
048
049    @Override
050    public List<Blob> getPreview(Blob blob, DocumentModel dm) throws PreviewException {
051        List<Blob> blobResults = new ArrayList<>();
052
053        byte[] data;
054        try {
055            data = blob.getByteArray();
056        } catch (IOException e) {
057            throw new PreviewException("Cannot fetch blob content", e);
058        }
059        String encoding = blob.getEncoding();
060        if (StringUtils.isEmpty(encoding)) {
061            CharsetDetector detector = new CharsetDetector();
062            detector.setText(data);
063            encoding = detector.detect().getName();
064        }
065
066        String content;
067        try {
068            content = new String(data, encoding);
069        } catch (UnsupportedEncodingException e) {
070            throw new PreviewException("Cannot encode blob content to string", e);
071        }
072
073        String html = PreviewHelper.makeHtmlPage(htmlContent(content));
074        Blob mainBlob = Blobs.createBlob(html, "text/html", "UTF-8", "index.html");
075
076        blobResults.add(mainBlob);
077        return blobResults;
078    }
079
080}