# AbstractEvaluatorSerializer.java

    /*
     *  Licensed to the Apache Software Foundation (ASF) under one
     *  or more contributor license agreements.  See the NOTICE file
     *  distributed with this work for additional information
     *  regarding copyright ownership.  The ASF licenses this file
     *  to you under the Apache License, Version 2.0 (the
     *  "License"); you may not use this file except in compliance
     *  with the License.  You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     *  Unless required by applicable law or agreed to in writing,
     *  software distributed under the License is distributed on an
     *   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     *  KIND, either express or implied.  See the License for the
     *  specific language governing permissions and limitations
     *  under the License.
     */

    package org.apache.synapse.commons.evaluators.config;

    import org.apache.axiom.om.OMElement;
    import org.apache.axiom.om.OMFactory;
    import org.apache.axiom.om.OMAbstractFactory;
    import org.apache.axiom.om.OMNamespace;
    import org.apache.synapse.commons.evaluators.Evaluator;
    import org.apache.synapse.commons.evaluators.EvaluatorException;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    /**
     * Provide common methods for {@link EvaluatorSerializer} implementations
     */
    public abstract class AbstractEvaluatorSerializer implements EvaluatorSerializer {

        protected Log log;

        protected static final OMFactory fac = OMAbstractFactory.getOMFactory();

        protected static final OMNamespace nullNS = fac.createOMNamespace("", "");

        /**
         * A constructor that makes subclasses pick up the correct logger
         */
        protected AbstractEvaluatorSerializer() {
            log = LogFactory.getLog(this.getClass());
        }

        protected void serializeChildren(OMElement parent, Evaluator[] childEvaluators)
                throws EvaluatorException {
            for (Evaluator evaluator : childEvaluators) {
                String name = evaluator.getName();

                EvaluatorSerializer serializer = EvaluatorSerializerFinder.
                        getInstance().getSerializer(name);

                if (serializer != null) {
                    serializer.serialize(parent, evaluator);
                } else {
                    String msg = "Couldn't find the serializer for evaliator: " + name;
                    log.error(msg);
                    throw new EvaluatorException(msg);
                }
            }
        }

        protected void serializeChild(OMElement parenet, Evaluator child) throws EvaluatorException {
            EvaluatorSerializer serializer =
                    EvaluatorSerializerFinder.getInstance().getSerializer(child.getName());

            if (serializer != null) {
                serializer.serialize(parenet, child);
            } else {
                String msg = "Couldn't find the serializer for evaliator: " + child.getName();
                log.error(msg);
                throw new EvaluatorException(msg);
            }
        }
    }