opcur/src/main/java/at/acdp/opcur/opc/ValueLoggingDelegate.java

/*
 * Copyright (c) 2016 Kevin Herron
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *   http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.html.
 */

package at.acdp.opcur.opc;


import org.eclipse.milo.opcua.sdk.server.api.nodes.VariableNode;
import org.eclipse.milo.opcua.sdk.server.nodes.AttributeContext;
import org.eclipse.milo.opcua.sdk.server.nodes.delegates.AttributeDelegate;
import org.eclipse.milo.opcua.sdk.server.nodes.delegates.DelegatingAttributeDelegate;
import org.eclipse.milo.opcua.stack.core.UaException;
import org.eclipse.milo.opcua.stack.core.types.builtin.DataValue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ValueLoggingDelegate extends DelegatingAttributeDelegate {

    private final Logger logger = LoggerFactory.getLogger(getClass());

    public ValueLoggingDelegate() {}

    public ValueLoggingDelegate(AttributeDelegate parent) {
        super(parent);
    }

    @Override
    public DataValue getValue(AttributeContext context, VariableNode node) throws UaException {
        DataValue value = super.getValue(context, node);

        // only log external reads
        if (context.getSession().isPresent()) {
            logger.info(
                    "getValue() nodeId={} value={}",
                    node.getNodeId(), value);
        }

        return value;
    }

    @Override
    public void setValue(AttributeContext context, VariableNode node, DataValue value) throws UaException {
        // only log external writes
        if (context.getSession().isPresent()) {
            logger.info(
                    "setValue() nodeId={} value={}",
                    node.getNodeId(), value);
        }

        super.setValue(context, node, value);
    }

}