/*

  * Copyright 2010 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.edl.impl.components;

 import java.util.ArrayList;

 import java.util.List;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.edl.impl.EDLContext;

 import org.kuali.rice.edl.impl.EDLModelComponent;

 import org.kuali.rice.edl.impl.RequestParser;

 import org.kuali.rice.edl.impl.UserAction;

 import org.w3c.dom.Document;

 import org.w3c.dom.Element;

 import org.w3c.dom.NodeList;

 public class RefreshFromLookupComponent implements EDLModelComponent {

         public void updateDOM(Document dom, Element configElement, EDLContext edlContext) {

                 String command = edlContext.getUserAction().getAction();

                 if (UserAction.ACTION_REFRESH_FROM_LOOKUP.equals(command)) {

                         RequestParser requestParser = edlContext.getRequestParser();

                         Element currentVersion = VersioningPreprocessor.findCurrentVersion(dom);

                         // First, create a list of all of the <field> tags that match the parameter names returned from the lookup

                         List<Element> fieldsToDelete = new ArrayList<Element>();

                         NodeList fieldNodes = currentVersion.getElementsByTagName("field");

                         // get the list of input parameters returned from the lookup so we can clear empty ones as well

                         List<String> requestParameterNames = requestParser.getParameterNames();

                         for (int i = 0; i < fieldNodes.getLength(); i++) {

                                 Element fieldNode = (Element) fieldNodes.item(i);

                                 String fieldName = fieldNode.getAttribute("name");

                                 if (requestParameterNames.contains(fieldName)) {

                                         fieldsToDelete.add(fieldNode);

                                 }

                         }

                         // Second, delete those nodes; we will rely on normal population to recreate those nodes

                         // if the nodes weren't deleted, EDL would continue to display the old value on the generated output

                         for (Element fieldToDelete : fieldsToDelete) {

                                 currentVersion.removeChild(fieldToDelete);

                         }

                 }

         }

 }