Examples with ReferenceResolver org.apache.sis.xml.ReferenceResolver used on opensource projects

Example 1 with ReferenceResolver

use of org.apache.sis.xml.ReferenceResolver in project sis by apache.

the class ObjectReference method resolve.

/**
 * If the given metadata object is null, tries to get an instance from the identifiers
 * declared in this {@code ObjectReference}. If the given metadata object is non-null,
 * assigns to that object the identifiers declared in this {@code ObjectReference}.
 *
 * <p>This method is invoked at unmarshalling time by {@link PropertyType#resolve(Context)}.</p>
 *
 * @param  <T>       the compile-time type of the {@code type} argument.
 * @param  context   the marshalling context, or {@code null} if none.
 * @param  type      the expected type of the metadata object.
 * @param  metadata  the metadata object, or {@code null}.
 * @return a metadata object for the identifiers, or {@code null}
 */
final <T> T resolve(final Context context, final Class<T> type, T metadata) {
    if (metadata == null) {
        final ReferenceResolver resolver = Context.resolver(context);
        if ((uuid == null || (metadata = resolver.resolve(context, type, uuid)) == null) && (xlink == null || (metadata = resolver.resolve(context, type, xlink)) == null)) {
            /*
                 * Failed to find an existing metadata instance.
                 * Creates an empty instance with the identifiers.
                 */
            int count = 0;
            SpecializedIdentifier<?>[] identifiers = new SpecializedIdentifier<?>[2];
            if (uuid != null)
                identifiers[count++] = new SpecializedIdentifier<>(IdentifierSpace.UUID, uuid);
            if (xlink != null)
                identifiers[count++] = new SpecializedIdentifier<>(IdentifierSpace.XLINK, xlink);
            identifiers = ArraysExt.resize(identifiers, count);
            metadata = resolver.newIdentifiedObject(context, type, identifiers);
        }
    } else {
        /*
             * In principle, the XML should contain a full metadata object OR a uuidref attribute.
             * However if both are present, assign the identifiers to that instance.
             */
        if (metadata instanceof IdentifiedObject) {
            final IdentifierMap map = ((IdentifiedObject) metadata).getIdentifierMap();
            putInto(context, map, IdentifierSpace.UUID, uuid);
            putInto(context, map, IdentifierSpace.XLINK, xlink);
        }
    }
    return metadata;
}