001/*
002 * (C) Copyright 2020 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 *     Nelson Silva <nsilva@nuxeo.com>
018 */
019
020package org.nuxeo.ecm.platform.preview.io;
021
022import static org.nuxeo.ecm.core.io.registry.reflect.Instantiations.SINGLETON;
023import static org.nuxeo.ecm.core.io.registry.reflect.Priorities.REFERENCE;
024
025import java.io.IOException;
026import java.net.URI;
027
028import org.nuxeo.ecm.core.api.Blob;
029import org.nuxeo.ecm.core.api.model.impl.primitives.BlobProperty;
030import org.nuxeo.ecm.core.blob.BlobManager;
031import org.nuxeo.ecm.core.blob.ManagedBlob;
032import org.nuxeo.ecm.core.io.marshallers.json.enrichers.AbstractJsonEnricher;
033import org.nuxeo.ecm.core.io.registry.reflect.Setup;
034import org.nuxeo.runtime.api.Framework;
035
036import com.fasterxml.jackson.core.JsonGenerator;
037
038/**
039 * Enriches {@link Blob} json with embed preview link when available.
040 * <p>
041 * Enabled when parameter enrichers-blob=preview is present.
042 * <p>
043 * Blob format is:
044 *
045 * <pre>
046 * {@code
047 * {
048 *  "name": "...",
049 *  "mime-type": "...",
050 *  ...
051 *  "preview": "<url>"
052 * }
053 * }
054 * </pre>
055 *
056 * @since 11.2
057 */
058@Setup(mode = SINGLETON, priority = REFERENCE)
059public class BlobPreviewJsonEnricher extends AbstractJsonEnricher<BlobProperty> {
060
061    public static final String NAME = "preview";
062
063    public BlobPreviewJsonEnricher() {
064        super(NAME);
065    }
066
067    @Override
068    public void write(JsonGenerator jg, BlobProperty blobProperty) throws IOException {
069        Blob blob = (Blob) blobProperty.getValue();
070        if (!(blob instanceof ManagedBlob)) {
071            return;
072        }
073
074        // if it's a managed blob try to use the embed uri for preview
075        BlobManager blobManager = Framework.getService(BlobManager.class);
076        URI uri = blobManager.getURI(blob, BlobManager.UsageHint.EMBED, null);
077        if (uri != null) {
078            jg.writeStringField(NAME, uri.toASCIIString());
079        }
080    }
081
082}