package org.jaxen;

 /*

  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/Navigator.java,v 1.30 2006/06/03 20:07:19 elharo Exp $

  * $Revision: 1.30 $

  * $Date: 2006/06/03 20:07:19 $

  *

  * ====================================================================

  *

  * Copyright 2000-2005 bob mcwhirter & James Strachan.

  * All rights reserved.

  *

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are

  * met:

  * 

  *   * Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  * 

  *   * Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in the

  *     documentation and/or other materials provided with the distribution.

  * 

  *   * Neither the name of the Jaxen Project nor the names of its

  *     contributors may be used to endorse or promote products derived 

  *     from this software without specific prior written permission.

  * 

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED

  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER

  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  *

  * ====================================================================

  * This software consists of voluntary contributions made by many

  * individuals on behalf of the Jaxen Project and was originally

  * created by bob mcwhirter <bob@werken.com> and

  * James Strachan <jstrachan@apache.org>.  For more information on the

  * Jaxen Project, please see <http://www.jaxen.org/>.

  *

  * $Id: Navigator.java,v 1.30 2006/06/03 20:07:19 elharo Exp $

 */

 import java.io.Serializable;

 import java.util.Iterator;

 import org.jaxen.saxpath.SAXPathException;

 /** Interface for navigating around an arbitrary object

  *  model, using XPath semantics.

  *

  *  <p>

  *  There is a method to obtain a <code>java.util.Iterator</code>,

  *  for each axis specified by XPath.  If the target object model

  *  does not support the semantics of a particular axis, an

  *  {@link UnsupportedAxisException} is to be thrown. If there are

  *  no nodes on that axis, an empty iterator should be returned.

  *  </p>

  *

  *  @author <a href="mailto:bob@eng.werken.com">bob mcwhirter</a>

  *  @author <a href="mailto:jstrachan@apache.org">James Strachan</a>

  *

  *  @version $Id: Navigator.java,v 1.30 2006/06/03 20:07:19 elharo Exp $

  */

 public interface Navigator extends Serializable

 {

     // ----------------------------------------------------------------------

     //     Axis Iterators

     // ----------------------------------------------------------------------

     /** Retrieve an <code>Iterator</code> matching the <code>child</code>

      *  XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the child axis are

      *          not supported by this object model

      */

     Iterator getChildAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>descendant</code>

      *  XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the desscendant axis are

      *          not supported by this object model

      */

     Iterator getDescendantAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>parent</code> XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the parent axis are

      *          not supported by this object model

      */

     Iterator getParentAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>ancestor</code>

      *  XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the ancestor axis are

      *          not supported by this object model

      */

     Iterator getAncestorAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the

      *  <code>following-sibling</code> XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the following-sibling axis are

      *          not supported by this object model

      */

     Iterator getFollowingSiblingAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the

      *  <code>preceding-sibling</code> XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the preceding-sibling axis are

      *          not supported by this object model

      */

     Iterator getPrecedingSiblingAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>following</code>

      *  XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the following axis are

      *          not supported by this object model

      */

     Iterator getFollowingAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>preceding</code> XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the preceding axis are

      *          not supported by this object model

      */

     Iterator getPrecedingAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>attribute</code>

      *  XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the attribute axis are

      *          not supported by this object model

      */

     Iterator getAttributeAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>namespace</code>

      *  XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the namespace axis are

      *          not supported by this object model

      */

     Iterator getNamespaceAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the <code>self</code> XPath

      *  axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the self axis are

      *          not supported by this object model

      */

     Iterator getSelfAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the

      *  <code>descendant-or-self</code> XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the descendant-or-self axis are

      *          not supported by this object model

      */

     Iterator getDescendantOrSelfAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve an <code>Iterator</code> matching the

      *  <code>ancestor-or-self</code> XPath axis.

      *

      *  @param contextNode the original context node

      *

      *  @return an Iterator capable of traversing the axis, not null

      *

      *  @throws UnsupportedAxisException if the semantics of the ancestor-or-self axis are

      *          not supported by this object model

      */

     Iterator getAncestorOrSelfAxisIterator(Object contextNode)

         throws UnsupportedAxisException;

     // ----------------------------------------------------------------------

     //     Extractors

     // ----------------------------------------------------------------------

     /** Loads a document from the given URI

      *

      *  @param uri the URI of the document to load

      *

      *  @return the document

      *

       * @throws FunctionCallException if the document could not be loaded

      */

     Object getDocument(String uri)

         throws FunctionCallException;

     /** Returns the document node that contains the given context node.

      *

      *  @see #isDocument(Object)

      *

      *  @param contextNode the context node

      *

      *  @return the document of the context node

      */

     Object getDocumentNode(Object contextNode);

     /** Returns the parent of the given context node.

      *

      *  <p>

      *  The parent of any node must either be a document

      *  node or an element node.

      *  </p>

      *

      *  @see #isDocument

      *  @see #isElement

      *

      *  @param contextNode the context node

      *

      *  @return the parent of the context node, or null if this is a document node.

      *

      *  @throws UnsupportedAxisException if the parent axis is not

      *          supported by the model

      */

     Object getParentNode(Object contextNode)

         throws UnsupportedAxisException;

     /** Retrieve the namespace URI of the given element node.

      *

      *  @param element the context element node

      *

      *  @return the namespace URI of the element node

      */

     String getElementNamespaceUri(Object element);    

     /** Retrieve the local name of the given element node.

      *

      *  @param element the context element node

      *

      *  @return the local name of the element node

      */

     String getElementName(Object element);    

     /** Retrieve the qualified name of the given element node.

      *

      *  @param element the context element node

      *

      *  @return the qualified name of the element node

      */

     String getElementQName(Object element);

     /** Retrieve the namespace URI of the given attribute node.

      *

      *  @param attr the context attribute node

      *

      *  @return the namespace URI of the attribute node

      */

     String getAttributeNamespaceUri(Object attr);    

     /** Retrieve the local name of the given attribute node.

      *

      *  @param attr the context attribute node

      *

      *  @return the local name of the attribute node

      */

     String getAttributeName(Object attr);

     /** Retrieve the qualified name of the given attribute node.

      *

      *  @param attr the context attribute node

      *

      *  @return the qualified name of the attribute node

      */

     String getAttributeQName(Object attr);

     /** Retrieve the target of a processing-instruction.

      *

      *  @param pi the context processing-instruction node

      *

      *  @return the target of the processing-instruction node

      */

     String getProcessingInstructionTarget(Object pi);

     /** Retrieve the data of a processing-instruction.

      *

      *  @param pi the context processing-instruction node

      *

      *  @return the data of the processing-instruction node

      */

     String getProcessingInstructionData(Object pi);

     // ----------------------------------------------------------------------

     //     isXXX testers

     // ----------------------------------------------------------------------

     /** Returns whether the given object is a document node. A document node

      *  is the node that is selected by the XPath expression <code>/</code>.

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is a document node,

      *          else <code>false</code>

      */

     boolean isDocument(Object object);

     /** Returns whether the given object is an element node.

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is an element node,

      *          else <code>false</code>

      */

     boolean isElement(Object object);

     /** Returns whether the given object is an attribute node. 

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is an attribute node,

      *          else <code>false</code>

      */

     boolean isAttribute(Object object);

     /** Returns whether the given object is a namespace node. 

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is a namespace node,

      *          else <code>false</code>

      */

     boolean isNamespace(Object object);

     /** Returns whether the given object is a comment node. 

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is a comment node,

      *          else <code>false</code>

      */

     boolean isComment(Object object);

     /** Returns whether the given object is a text node. 

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is a text node,

      *          else <code>false</code>

      */

     boolean isText(Object object);

     /** Returns whether the given object is a processing-instruction node.

      *

      *  @param object the object to test

      *

      *  @return <code>true</code> if the object is a processing-instruction node,

      *          else <code>false</code>

      */

     boolean isProcessingInstruction(Object object);

     // ----------------------------------------------------------------------

     //     String-Value extractors

     // ----------------------------------------------------------------------

     /** Retrieve the string-value of a comment node.

      * This may be the empty string if the comment is empty,

      * but must not be null.

      *

      *  @param comment the comment node

      *

      *  @return the string-value of the node

      */

     String getCommentStringValue(Object comment);

     /** Retrieve the string-value of an element node.

      * This may be the empty string if the element is empty,

      * but must not be null.

      *

      *  @param element the comment node.

      *

      *  @return the string-value of the node.

      */

     String getElementStringValue(Object element);

     /** Retrieve the string-value of an attribute node. 

      *  This should be the XML 1.0 normalized attribute value.

      *  This may be the empty string but must not be null. 

      *

      *  @param attr the attribute node

      *

      *  @return the string-value of the node

      */

     String getAttributeStringValue(Object attr);

     /** Retrieve the string-value of a namespace node.

      * This is generally the namespace URI.

      * This may be the empty string but must not be null.

      *

      *  @param ns the namespace node

      *

      *  @return the string-value of the node

      */

     String getNamespaceStringValue(Object ns);

     /** Retrieve the string-value of a text node.

      * This must not be null and should not be the empty string.

      * The XPath data model does not allow empty text nodes.

      *

      *  @param text the text node

      *

      *  @return the string-value of the node

      */

     String getTextStringValue(Object text);

     // ----------------------------------------------------------------------

     //     General utilities

     // ----------------------------------------------------------------------

     /** Retrieve the namespace prefix of a namespace node.

      *

      *  @param ns the namespace node

      *

      *  @return the prefix associated with the node

      */

     String getNamespacePrefix(Object ns);

     /** Translate a namespace prefix to a namespace URI, <strong>possibly</strong>

      *  considering a particular element node.

      *

      *  <p>

      *  Strictly speaking, prefix-to-URI translation should occur

      *  irrespective of any element in the document.  This method

      *  is provided to allow a non-conforming ease-of-use enhancement.

      *  </p>

      *

      *  @see NamespaceContext

      *

      *  @param prefix the prefix to translate

      *  @param element the element to consider during translation

      *

      *  @return the namespace URI associated with the prefix

      */

     String translateNamespacePrefixToUri(String prefix,

                                          Object element);

     /** Returns a parsed form of the given XPath string, which will be suitable

      *  for queries on documents that use the same navigator as this one.

      *

      *  @see XPath

      *

      *  @param xpath the XPath expression

      *

      *  @return a new XPath expression object

      *

      *  @throws SAXPathException if the string is not a syntactically 

      *      correct XPath expression

      */

     XPath parseXPath(String xpath) throws SAXPathException;

     /**

      *  Returns the element whose ID is given by elementId.

      *  If no such element exists, returns null.

      *  Attributes with the name "ID" are not of type ID unless so defined.

      *  Implementations that do not know whether attributes are of type ID or

      *  not are expected to return null.

      *

      *  @param contextNode   a node from the document in which to look for the

      *                       id

      *  @param elementId   id to look for

      *

      *  @return   element whose ID is given by elementId, or null if no such

      *            element exists in the document or if the implementation

      *            does not know about attribute types

      */

     Object getElementById(Object contextNode,

                           String elementId);

     /** Returns a number that identifies the type of node that the given

      *  object represents in this navigator.

      * 

      * @param node ????

      * @return ????

      *

      *  @see org.jaxen.pattern.Pattern

      */

     short getNodeType(Object node);

 }