domelement.hpp

基于属性证书的访问控制源代码,由c++编写,包括openssl,xercesc等

#ifndef DOMElement_HEADER_GUARD_
#define DOMElement_HEADER_GUARD_

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache\@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * 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 Apache Software Foundation, and was
 * originally based on software copyright (c) 2001, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/*
 * $Id: DOMElement.hpp,v 1.9 2003/03/07 19:59:03 tng Exp $
 */

#include <xercesc/util/XercesDefs.hpp>
#include "DOMNode.hpp"

XERCES_CPP_NAMESPACE_BEGIN


class DOMAttr;
class DOMNodeList;
class DOMTypeInfo;


/**
 * By far the vast majority of objects (apart from text) that authors
 * encounter when traversing a document are <code>DOMElement</code> nodes.
 *
 * Assume the following XML document:&lt;elementExample id="demo"&gt;
 * &lt;subelement1/&gt;
 * &lt;subelement2&gt;&lt;subsubelement/&gt;&lt;/subelement2&gt;
 * &lt;/elementExample&gt;
 * <p>When represented using DOM, the top node is an <code>DOMElement</code> node
 * for "elementExample", which contains two child <code>DOMElement</code> nodes,
 * one for "subelement1" and one for "subelement2". "subelement1" contains no
 * child nodes.
 * <p>Elements may have attributes associated with them; since the
 * <code>DOMElement</code> interface inherits from <code>DOMNode</code>, the generic
 *  <code>DOMNode</code> interface method <code>getAttributes</code> may be used
 * to retrieve the set of all attributes for an element.  There are methods on
 *  the <code>DOMElement</code> interface to retrieve either an <code>DOMAttr</code>
 *  object by name or an attribute value by name. In XML, where an attribute
 * value may contain entity references, an <code>DOMAttr</code> object should be
 * retrieved to examine the possibly fairly complex sub-tree representing the
 * attribute value. On the other hand, in HTML, where all attributes have
 * simple string values, methods to directly access an attribute value can
 * safely be used as a convenience.
 *
 * @since DOM Level 1
 */

class CDOM_EXPORT DOMElement: public DOMNode {
protected:
    // -----------------------------------------------------------------------
    //  Hidden constructors
    // -----------------------------------------------------------------------
    /** @name Hidden constructors */
    //@{    
    DOMElement() {};
    //@}
    
private:
    // -----------------------------------------------------------------------
    // Unimplemented constructors and operators
    // -----------------------------------------------------------------------
    /** @name Unimplemented constructors and operators */
    //@{
    DOMElement(const DOMElement &);
    DOMElement & operator = (const DOMElement &);
    //@}

public:
    // -----------------------------------------------------------------------
    //  All constructors are hidden, just the destructor is available
    // -----------------------------------------------------------------------
    /** @name Destructor */
    //@{
    /**
     * Destructor
     *
     */
    virtual ~DOMElement() {};
    //@}

    // -----------------------------------------------------------------------
    //  Virtual DOMElement interface
    // -----------------------------------------------------------------------
    /** @name Functions introduced in DOM Level 1 */
    //@{
    // -----------------------------------------------------------------------
    //  Getter methods
    // -----------------------------------------------------------------------
    /**
     * The name of the element.
     *
     * For example, in: &lt;elementExample
     * id="demo"&gt;  ... &lt;/elementExample&gt; , <code>tagName</code> has
     * the value <code>"elementExample"</code>. Note that this is
     * case-preserving in XML, as are all of the operations of the DOM.
     * @since DOM Level 1
     */
    virtual const XMLCh *         getTagName() const = 0;

    /**
     * Retrieves an attribute value by name.
     *
     * @param name The name of the attribute to retrieve.
     * @return The <code>DOMAttr</code> value as a string, or the empty  string if
     *   that attribute does not have a specified or default value.
     * @since DOM Level 1
     */
    virtual const XMLCh *         getAttribute(const XMLCh *name) const = 0;

    /**
     * Retrieves an <code>DOMAttr</code> node by name.
     *
     * @param name The name (<CODE>nodeName</CODE>) of the attribute to retrieve.
     * @return The <code>DOMAttr</code> node with the specified name (<CODE>nodeName</CODE>) or
     *   <code>null</code> if there is no such attribute.
     * @since DOM Level 1
     */
    virtual DOMAttr       * getAttributeNode(const XMLCh *name) const = 0;

    /**
     * Returns a <code>DOMNodeList</code> of all descendant elements with a given
     * tag name, in the order in which they would be encountered in a preorder
     * traversal of the <code>DOMElement</code> tree.
     *
     * @param name The name of the tag to match on. The special value "*"
     *   matches all tags.
     * @return A list of matching <code>DOMElement</code> nodes.
     * @since DOM Level 1
     */
    virtual DOMNodeList   * getElementsByTagName(const XMLCh *name) const = 0;

    // -----------------------------------------------------------------------
    //  Setter methods
    // -----------------------------------------------------------------------
    /**
     * Adds a new attribute.
     *
     * If an attribute with that name is already present
     * in the element, its value is changed to be that of the value parameter.
     * This value is a simple string, it is not parsed as it is being set. So
     * any markup (such as syntax to be recognized as an entity reference) is
     * treated as literal text, and needs to be appropriately escaped by the
     * implementation when it is written out. In order to assign an attribute
     * value that contains entity references, the user must create an
     * <code>DOMAttr</code> node plus any <code>DOMText</code> and
     * <code>DOMEntityReference</code> nodes, build the appropriate subtree, and
     * use <code>setAttributeNode</code> to assign it as the value of an
     * attribute.
     * @param name The name of the attribute to create or alter.
     * @param value Value to set in string form.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified name contains an
     *   illegal character.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
     * @since DOM Level 1
     */
    virtual void             setAttribute(const XMLCh *name,
                                  const XMLCh *value) = 0;
    /**
     * Adds a new attribute.
     *
     * If an attribute with that name (<CODE>nodeName</CODE>) is already present
     * in the element, it is replaced by the new one.
     * @param newAttr The <code>DOMAttr</code> node to add to the attribute list.
     * @return If the <code>newAttr</code> attribute replaces an existing
     *   attribute, the replaced
     *   <code>DOMAttr</code> node is returned, otherwise <code>null</code> is
     *   returned.
     * @exception DOMException
     *   WRONG_DOCUMENT_ERR: Raised if <code>newAttr</code> was created from a
     *   different document than the one that created the element.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
     *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>newAttr</code> is already an
     *   attribute of another <code>DOMElement</code> object. The DOM user must
     *   explicitly clone <code>DOMAttr</code> nodes to re-use them in other
     *   elements.
     * @since DOM Level 1
     */
    virtual DOMAttr       * setAttributeNode(DOMAttr *newAttr) = 0;

    /**
     * Removes the specified attribute node.
     * If the removed <CODE>DOMAttr</CODE>
     *   has a default value it is immediately replaced. The replacing attribute
     *   has the same namespace URI and local name, as well as the original prefix,
     *   when applicable.
     *
     * @param oldAttr The <code>DOMAttr</code> node to remove from the attribute
     *   list.
     * @return The <code>DOMAttr</code> node that was removed.
     * @exception DOMException
     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
     *   <br>NOT_FOUND_ERR: Raised if <code>oldAttr</code> is not an attribute
     *   of the element.
     * @since DOM Level 1
     */
    virtual DOMAttr       * removeAttributeNode(DOMAttr *oldAttr) = 0;

    /**
     * Removes an attribute by name.
     *
     * If the removed attribute