001/*
002 * (C) Copyright 2010 Nuxeo SA (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 * Contributors:
016 * Nuxeo - initial API and implementation
017 */
018
019package org.nuxeo.ecm.platform.rendition.impl;
020
021import java.util.List;
022
023import org.nuxeo.ecm.core.api.Blob;
024import org.nuxeo.ecm.platform.rendition.Rendition;
025import org.nuxeo.ecm.platform.rendition.service.RenditionDefinition;
026
027/**
028 * Implementation of the {@link Rendition} interface that allows lazy computation of the rendition Blobs
029 *
030 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a>
031 */
032public abstract class LazyRendition extends AbstractRendition implements Rendition {
033
034    public static final String EMPTY_MARKER = "empty=true";
035
036    public static final String ERROR_MARKER = "error=true";
037
038    protected List<Blob> blobs = null;
039
040    public LazyRendition(RenditionDefinition definition) {
041        super(definition);
042    }
043
044    @Override
045    public Blob getBlob() {
046        List<Blob> blobs = getBlobs();
047        if (blobs != null && blobs.size() > 0) {
048            return blobs.get(0);
049        }
050        return null;
051    }
052
053    @Override
054    public List<Blob> getBlobs() {
055        if (blobs == null) {
056            blobs = computeRenditionBlobs();
057        }
058        return blobs;
059    }
060
061    @Override
062    public boolean isCompleted() {
063        Blob blob = getBlob();
064        if (blob == null) {
065            return true;
066        }
067        String mimeType = blob.getMimeType();
068        // lazy rendition with build in-progress has blob mimeType containing "empty=true"
069        return mimeType == null || !mimeType.contains(EMPTY_MARKER);
070    }
071
072    protected abstract List<Blob> computeRenditionBlobs();
073
074}