/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.core.impl.impex.xml;

 import static org.kuali.rice.core.api.impex.xml.XmlConstants.DATA_ELEMENT;

 import static org.kuali.rice.core.api.impex.xml.XmlConstants.SCHEMA_LOCATION_ATTR;

 import static org.kuali.rice.core.api.impex.xml.XmlConstants.SCHEMA_NAMESPACE;

 import static org.kuali.rice.core.api.impex.xml.XmlConstants.WORKFLOW_NAMESPACE;

 import static org.kuali.rice.core.api.impex.xml.XmlConstants.WORKFLOW_SCHEMA_LOCATION;

 import java.io.IOException;

 import java.io.StringWriter;

 import org.jdom.Document;

 import org.jdom.Element;

 import org.jdom.output.Format;

 import org.jdom.output.XMLOutputter;

 import org.kuali.rice.core.api.impex.ExportDataSet;

 import org.kuali.rice.core.api.impex.xml.XmlExporterService;

 import org.kuali.rice.core.framework.impex.xml.XmlExporter;

 import org.kuali.rice.core.framework.impex.xml.XmlImpexRegistry;

 import org.kuali.rice.kew.api.WorkflowRuntimeException;

 /**

  * An implementation of the XmlExporterService which can be configured with a set of

  * services that know how to export various pieces of the {@link ExportDataSet} to XML.

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class XmlExporterServiceImpl implements XmlExporterService {

          private XmlImpexRegistry xmlImpexRegistry;

     public byte[] export(ExportDataSet dataSet) {

         if (dataSet == null) {

             throw new IllegalArgumentException("Xml Exporter cannot handle NULL data.");

         }

         Element rootElement = new Element(DATA_ELEMENT, WORKFLOW_NAMESPACE);

         rootElement.addNamespaceDeclaration(SCHEMA_NAMESPACE);

         rootElement.setAttribute(SCHEMA_LOCATION_ATTR, WORKFLOW_SCHEMA_LOCATION, SCHEMA_NAMESPACE);

         Document document = new Document(rootElement);

         boolean shouldPrettyPrint = true;

         for (XmlExporter exporter : xmlImpexRegistry.getExporters()) {

                 Element exportedElement = exporter.export(dataSet);

                 if (exportedElement != null) {

                         if (!exporter.supportPrettyPrint()) {

                                 shouldPrettyPrint = false;

                         }

                         appendIfNotEmpty(rootElement, exportedElement);

                 }

         }

         // TODO: KULRICE-4420 - this needs cleanup

         Format f;

         if (!shouldPrettyPrint) {

             f = Format.getRawFormat();

             f.setExpandEmptyElements(false);

             f.setTextMode(Format.TextMode.PRESERVE);

         } else {

             f = Format.getPrettyFormat();

         }

         XMLOutputter outputer = new XMLOutputter(f);

         StringWriter writer = new StringWriter();

         try {

             outputer.output(document, writer);

         } catch (IOException e) {

             throw new WorkflowRuntimeException("Could not write XML data export.", e);

         }

         return writer.toString().getBytes();

     }

     private void appendIfNotEmpty(Element parent, Element child) {

         if (child != null) {

             parent.addContent(child);

         }

     }

     public void setXmlImpexRegistry(XmlImpexRegistry xmlImpexRegistry) {

             this.xmlImpexRegistry = xmlImpexRegistry;

     }

 }