001/*
002 * (C) Copyright 2015 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 *
016 * Contributors:
017 *     Nicolas Chapurlat <nchapurlat@nuxeo.com>
018 */
019
020package org.nuxeo.ecm.core.io.marshallers.json.enrichers;
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;
026
027import org.nuxeo.ecm.core.api.DocumentModel;
028import org.nuxeo.ecm.core.api.DocumentModelList;
029import org.nuxeo.ecm.core.io.marshallers.json.document.DocumentModelListJsonWriter;
030import org.nuxeo.ecm.core.io.registry.context.RenderingContext.SessionWrapper;
031import org.nuxeo.ecm.core.io.registry.reflect.Setup;
032
033import com.fasterxml.jackson.core.JsonGenerator;
034
035/**
036 * Enrich {@link DocumentModel} Json.
037 * <p>
038 * Add document children (list of document) as json attachment.
039 * <p>
040 * Enable if parameter enrichers-document=children is present.
041 * <p>
042 * Format is:
043 *
044 * <pre>
045 * {
046 *   "entity-type":"document",
047 *   ...
048 *   "contextParameters": {
049 *     "children": { see {@link DocumentModelListJsonWriter} for format }
050 *   }
051 * }
052 * </pre>
053 *
054 * @since 7.2
055 */
056@Setup(mode = SINGLETON, priority = REFERENCE)
057public class ChildrenJsonEnricher extends AbstractJsonEnricher<DocumentModel> {
058
059    public static final String NAME = "children";
060
061    public ChildrenJsonEnricher() {
062        super(NAME);
063    }
064
065    @Override
066    public void write(JsonGenerator jg, DocumentModel document) throws IOException {
067        DocumentModelList children = null;
068        try (SessionWrapper wrapper = ctx.getSession(document)) {
069            children = wrapper.getSession().getChildren(document.getRef());
070        }
071        jg.writeFieldName(NAME);
072        writeEntity(children, jg);
073    }
074
075}