org.emfjson.jackson.databind.ser.EcoreReferenceSerializer.java Source code

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Here is the source code for org.emfjson.jackson.databind.ser.EcoreReferenceSerializer.java

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/*
 * Copyright (c) 2015 Guillaume Hillairet.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Guillaume Hillairet - initial API and implementation
 *
 */
package org.emfjson.jackson.databind.ser;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.InternalEObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.emfjson.jackson.annotations.EcoreReferenceInfo;
import org.emfjson.jackson.databind.EMFContext;
import org.emfjson.jackson.handlers.URIHandler;
import org.emfjson.jackson.utils.Cache;

import java.io.IOException;

public class EcoreReferenceSerializer extends JsonSerializer<EObject> {

    private final EcoreReferenceInfo.Base info;
    private final URIHandler handler;

    public EcoreReferenceSerializer(EcoreReferenceInfo.Base info, URIHandler handler) {
        this.info = info;
        this.handler = handler;
    }

    @Override
    public void serialize(EObject value, JsonGenerator jg, SerializerProvider serializers) throws IOException {
        final EObject parent = EMFContext.getParent(serializers);
        final Cache cache = EMFContext.getCache(serializers);
        final String href = getHRef(cache, parent, value);

        jg.writeStartObject();
        jg.writeStringField(info.getTypeProperty(), cache.getURI(value.eClass()));
        if (href == null) {
            jg.writeNullField(info.getProperty());
        } else {
            jg.writeStringField(info.getProperty(), href);
        }
        jg.writeEndObject();
    }

    protected boolean isExternal(EObject source, EObject target) {
        final Resource sourceResource = ((InternalEObject) source).eInternalResource();
        if (target.eIsProxy()) {
            final URI uri = ((InternalEObject) target).eProxyURI();

            return sourceResource != null && sourceResource.getURI() != null
                    && !sourceResource.getURI().equals(uri.trimFragment());
        }

        return sourceResource == null || sourceResource != ((InternalEObject) target).eInternalResource();
    }

    protected String getHRef(Cache cache, EObject parent, EObject value) {
        if (isExternal(parent, value)) {
            final URI targetURI = cache.getURI(value);
            final URI sourceURI = cache.getURI(parent);
            final URI deresolved = handler != null ? handler.deresolve(sourceURI, targetURI) : targetURI;

            return deresolved == null ? null : deresolved.toString();
        } else {
            return value.eResource().getURIFragment(value);
        }
    }
}