# JavaScriptXmlHelper.java

    /*
    *  Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
    *
    *  WSO2 Inc. 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.mediators.bsf;

    import org.apache.axiom.om.OMElement;
    import org.apache.axiom.om.util.AXIOMUtil;
    import org.apache.bsf.xml.DefaultXMLHelper;
    import org.apache.xmlbeans.XmlException;
    import org.apache.xmlbeans.XmlObject;
    import org.mozilla.javascript.Context;
    import org.mozilla.javascript.Scriptable;
    import org.mozilla.javascript.ScriptableObject;
    import org.mozilla.javascript.xml.XMLObject;

    import javax.script.ScriptException;
    import javax.xml.stream.XMLStreamException;

    /**
     * This class will provide the operation to getPayloadXML and setPayload of CommonScriptMessageContext to convert
     * between XML and ScriptXML object
     * since there is an api change in rhino17,This class is provided instead of getting Helper class by
     * XMLHelper.getArgHelper(engine) in bsf
     */

    public class JavaScriptXmlHelper extends DefaultXMLHelper {
        private final Scriptable scope;

        JavaScriptXmlHelper() {
            Context cx = Context.enter();
            try {
                this.scope = cx.initStandardObjects();
            } finally {
                Context.exit();
            }
        }

        /**
         * This method will convert the message payload in to xml
         *
         * @param scriptXML from java script Scriptable
         * @return XML content as OMElement wrapped in Scriptable object
         * @throws ScriptException when error
         */
        public OMElement toOMElement(Object scriptXML)
                throws ScriptException {
            if (scriptXML == null) {
                return null;
            }
            if (!(scriptXML instanceof XMLObject)) {
                return null;
            }
            // TODO: E4X Bug? Shouldn't need this copy, but without it the outer element gets lost???
            Scriptable jsXML = (Scriptable) ScriptableObject.callMethod((Scriptable) scriptXML, "copy", new Object[0]);

            OMElement omElement;

            try {
                omElement = AXIOMUtil.stringToOM((String) ScriptableObject.callMethod(jsXML, "toXMLString", new Object[0]));
            } catch (XMLStreamException e) {
                throw new ScriptException(e);
            }

            return omElement;
        }

        /**
         * This method will convert the message payload in to ScriptXML Object
         *
         * @param omElement
         * @return Scriptable object by adding the xml content
         * @throws ScriptException when error
         */
        public Object toScriptXML(OMElement omElement)
                throws ScriptException {
            if (omElement == null) {
                return null;
            }
            Context cx = Context.enter();
            try {
                XmlObject xml;
                try {
                    xml = XmlObject.Factory.parse(omElement.getXMLStreamReader());
                } catch (XmlException e) {
                    throw new ScriptException(e);
                }
                Object wrappedXML = cx.getWrapFactory().wrap(cx, this.scope, xml, XmlObject.class);
                Object obj = cx.newObject(this.scope, "XML", new Object[]{wrappedXML});
                return obj;
            } finally {
                Context.exit();
            }
        }
    }