code: /**
   * 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.cxf.ws.security.policy.builders;
  
  import javax.xml.namespace.QName;
  
  import org.w3c.dom.Attr;
  import org.w3c.dom.Element;
  import org.w3c.dom.NamedNodeMap;
  import org.w3c.dom.Node;
  
  import org.apache.cxf.helpers.DOMUtils;
  import org.apache.cxf.ws.security.policy.SP11Constants;
  import org.apache.cxf.ws.security.policy.SP12Constants;
  import org.apache.cxf.ws.security.policy.SPConstants;
  import org.apache.cxf.ws.security.policy.model.RequiredElements;
  import org.apache.neethi.Assertion;
  import org.apache.neethi.AssertionBuilderFactory;
  import org.apache.neethi.builders.AssertionBuilder;
  
  
  public class RequiredElementsBuilder implements AssertionBuilder<Element> {
      
      public QName[] getKnownElements() {
          return new QName[]{SP11Constants.REQUIRED_ELEMENTS, SP12Constants.REQUIRED_ELEMENTS};
      }
  
      public Assertion build(Element element, AssertionBuilderFactory factory)
          throws IllegalArgumentException {
  
          SPConstants consts = SP11Constants.SP_NS.equals(element.getNamespaceURI())
              ? SP11Constants.INSTANCE : SP12Constants.INSTANCE;
  
          RequiredElements requiredElements = new RequiredElements(consts);
          String attrXPathVersion = element.getAttributeNS(consts.getNamespace(), SPConstants.XPATH_VERSION);
  
          if (attrXPathVersion != null) {
              requiredElements.setXPathVersion(attrXPathVersion);
          }
  
  
          Node nd = element.getFirstChild();
          while (nd != null) {
              if (nd instanceof Element) {
                  processElement((Element)nd, requiredElements);                
              }
              nd = nd.getNextSibling();
          }
          return requiredElements;
      }
  
      private void processElement(Element element, RequiredElements parent) {
          if (SPConstants.XPATH_EXPR.equals(element.getLocalName())) {
              parent.addXPathExpression(DOMUtils.getRawContent(element));
              addNamespaces(element, parent);
          }
      }
      private void addNamespaces(Node element, RequiredElements parent) {
          if (element.getParentNode() != null) {
              addNamespaces(element.getParentNode(), parent);
          }
          if (element instanceof Element) {
              Element el = (Element)element;
              NamedNodeMap map = el.getAttributes();
              for (int x = 0; x < map.getLength(); x++) {
                  Attr attr = (Attr)map.item(x);
                  if ("xmlns".equals(attr.getPrefix())) {
                      parent.addDeclaredNamespaces(attr.getValue(), attr.getLocalName());
                  }
              }
          }
      }
  
  }
  