src/org/apache/xml/security/transforms/params/XPath2FilterContainer04.java

/*
 * Copyright  1999-2004 The Apache Software Foundation.
 *
 *  Licensed 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.xml.security.transforms.params;



import org.apache.xml.security.exceptions.XMLSecurityException;
import org.apache.xml.security.transforms.TransformParam;
import org.apache.xml.security.utils.ElementProxy;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;


/**
 * Implements the parameters for the <A
 * HREF="http://www.w3.org/TR/xmldsig-filter2/">XPath Filter v2.0</A>.
 *
 * @author $Author$
 * @see <A HREF="http://www.w3.org/TR/xmldsig-filter2/">XPath Filter v2.0 (TR)</A>
 * @see <A HREF="http://www.w3.org/Signature/Drafts/xmldsig-xfilter2/">XPath Filter v2.0 (editors copy)</A>
 */
public class XPath2FilterContainer04 extends ElementProxy
        implements TransformParam {

   /** Field _ATT_FILTER */
   private static final String _ATT_FILTER = "Filter";

   /** Field _ATT_FILTER_VALUE_INTERSECT */
   private static final String _ATT_FILTER_VALUE_INTERSECT = "intersect";

   /** Field _ATT_FILTER_VALUE_SUBTRACT */
   private static final String _ATT_FILTER_VALUE_SUBTRACT = "subtract";

   /** Field _ATT_FILTER_VALUE_UNION */
   private static final String _ATT_FILTER_VALUE_UNION = "union";

   /** Field _TAG_XPATH2 */
   public static final String _TAG_XPATH2 = "XPath";

   /** Field XPathFiler2NS */
   public static final String XPathFilter2NS =
      "http://www.w3.org/2002/04/xmldsig-filter2";

   /**
    * Constructor XPath2FilterContainer04
    *
    */
   private XPath2FilterContainer04() {

      // no instantiation
   }

   /**
    * Constructor XPath2FilterContainer04
    *
    * @param doc
    * @param xpath2filter
    * @param filterType
    */
   private XPath2FilterContainer04(Document doc, String xpath2filter,
                                 String filterType) {

      super(doc);

      this._constructionElement.setAttributeNS(null, XPath2FilterContainer04._ATT_FILTER,
                                             filterType);

      if ((xpath2filter.length() > 2)
              && (!Character.isWhitespace(xpath2filter.charAt(0)))) {
         this._constructionElement.appendChild(doc.createTextNode("\n"
                 + xpath2filter + "\n"));
      } else {
         this._constructionElement
            .appendChild(doc.createTextNode(xpath2filter));
      }
   }

   /**
    * Constructor XPath2FilterContainer04
    *
    * @param element
    * @param BaseURI
    * @throws XMLSecurityException
    */
   private XPath2FilterContainer04(Element element, String BaseURI)
           throws XMLSecurityException {

      super(element, BaseURI);

      String filterStr =
         this._constructionElement
            .getAttributeNS(null, XPath2FilterContainer04._ATT_FILTER);

      if (!filterStr
              .equals(XPath2FilterContainer04
              ._ATT_FILTER_VALUE_INTERSECT) &&!filterStr
                 .equals(XPath2FilterContainer04
                 ._ATT_FILTER_VALUE_SUBTRACT) &&!filterStr
                    .equals(XPath2FilterContainer04._ATT_FILTER_VALUE_UNION)) {
         Object exArgs[] = { XPath2FilterContainer04._ATT_FILTER, filterStr,
                             XPath2FilterContainer04._ATT_FILTER_VALUE_INTERSECT
                             + ", "
                             + XPath2FilterContainer04._ATT_FILTER_VALUE_SUBTRACT
                             + " or "
                             + XPath2FilterContainer04._ATT_FILTER_VALUE_UNION };

         throw new XMLSecurityException("attributeValueIllegal", exArgs);
      }
   }

   /**
    * Creates a new XPath2FilterContainer04 with the filter type "intersect".
    *
    * @param doc
    * @param xpath2filter
    * @return the instance
    */
   public static XPath2FilterContainer04 newInstanceIntersect(Document doc,
           String xpath2filter) {

      return new XPath2FilterContainer04(doc, xpath2filter,
                                       XPath2FilterContainer04
                                          ._ATT_FILTER_VALUE_INTERSECT);
   }

   /**
    * Creates a new XPath2FilterContainer04 with the filter type "subtract".
    *
    * @param doc
    * @param xpath2filter
    * @return the instance
    */
   public static XPath2FilterContainer04 newInstanceSubtract(Document doc,
           String xpath2filter) {

      return new XPath2FilterContainer04(doc, xpath2filter,
                                       XPath2FilterContainer04
                                          ._ATT_FILTER_VALUE_SUBTRACT);
   }

   /**
    * Creates a new XPath2FilterContainer04 with the filter type "union".
    *
    * @param doc
    * @param xpath2filter
    * @return the instance
    */
   public static XPath2FilterContainer04 newInstanceUnion(Document doc,
           String xpath2filter) {

      return new XPath2FilterContainer04(doc, xpath2filter,
                                       XPath2FilterContainer04
                                          ._ATT_FILTER_VALUE_UNION);
   }

   /**
    * Creates a XPath2FilterContainer04 from an existing Element; needed for verification.
    *
    * @param element
    * @param BaseURI
    * @return the instance
    *
    * @throws XMLSecurityException
    */
   public static XPath2FilterContainer04 newInstance(
           Element element, String BaseURI) throws XMLSecurityException {
      return new XPath2FilterContainer04(element, BaseURI);
   }

   /**
    * Returns <code>true</code> if the <code>Filter</code> attribute has value "intersect".
    *
    * @return <code>true</code> if the <code>Filter</code> attribute has value "intersect".
    */
   public boolean isIntersect() {

      return this._constructionElement
         .getAttributeNS(null, XPath2FilterContainer04._ATT_FILTER)
         .equals(XPath2FilterContainer04._ATT_FILTER_VALUE_INTERSECT);
   }

   /**
    * Returns <code>true</code> if the <code>Filter</code> attribute has value "subtract".
    *
    * @return <code>true</code> if the <code>Filter</code> attribute has value "subtract".
    */
   public boolean isSubtract() {

      return this._constructionElement
         .getAttributeNS(null, XPath2FilterContainer04._ATT_FILTER)
         .equals(XPath2FilterContainer04._ATT_FILTER_VALUE_SUBTRACT);
   }

   /**
    * Returns <code>true</code> if the <code>Filter</code> attribute has value "union".
    *
    * @return <code>true</code> if the <code>Filter</code> attribute has value "union".
    */
   public boolean isUnion() {

      return this._constructionElement
         .getAttributeNS(null, XPath2FilterContainer04._ATT_FILTER)
         .equals(XPath2FilterContainer04._ATT_FILTER_VALUE_UNION);
   }

   /**
    * Returns the XPath 2 Filter String
    *
    * @return the XPath 2 Filter String
    */
   public String getXPathFilterStr() {
      return this.getTextFromTextChild();
   }

   /**
    * Returns the first Text node which contains information from the XPath 2
    * Filter String. We must use this stupid hook to enable the here() function
    * to work.
    *
    * $todo$ I dunno whether this crashes: <XPath> here()<!-- comment -->/ds:Signature[1]</XPath>
    * @return the first Text node which contains information from the XPath 2 Filter String
    */
   public Node getXPathFilterTextNode() {
      NodeList children = this._constructionElement.getChildNodes();
      int length = children.getLength();

      for (int i = 0; i < length; i++) {
         if (children.item(i).getNodeType() == Node.TEXT_NODE) {
            return children.item(i);
         }
      }

      return null;
   }

   /** @inheritDoc */
   public final String getBaseLocalName() {
      return XPath2FilterContainer04._TAG_XPATH2;
   }

   /** @inheritDoc */
   public final String getBaseNamespace() {
      return XPath2FilterContainer04.XPathFilter2NS;
   }
}