/*

 * 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.

 */

/*

 * $Id: DOM_DocumentFragment.hpp 568078 2007-08-21 11:43:25Z amassari $

 */

#ifndef DOM_DocumentFragment_HEADER_GUARD_

#define DOM_DocumentFragment_HEADER_GUARD_

#include <xercesc/util/XercesDefs.hpp>

#include "DOM_Node.hpp"

XERCES_CPP_NAMESPACE_BEGIN

class DocumentFragmentImpl;

/**

 * <code>DocumentFragment</code> is a "lightweight" or "minimal"

 * <code>Document</code> object.

 *

 * It is very common to want to be able to

 * extract a portion of a document's tree or to create a new fragment of a

 * document. Imagine implementing a user command like cut or rearranging a

 * document by moving fragments around. It is desirable to have an object

 * which can hold such fragments and it is quite natural to use a Node for

 * this purpose. While it is true that a <code>Document</code> object could

 * fulfil this role,  a <code>Document</code> object can potentially be a

 * heavyweight  object, depending on the underlying implementation. What is

 * really needed for this is a very lightweight object.

 * <code>DocumentFragment</code> is such an object.

 * <p>Furthermore, various operations -- such as inserting nodes as children

 * of another <code>Node</code> -- may take <code>DocumentFragment</code>

 * objects as arguments;  this results in all the child nodes of the

 * <code>DocumentFragment</code>  being moved to the child list of this node.

 * <p>The children of a <code>DocumentFragment</code> node are zero or more

 * nodes representing the tops of any sub-trees defining the structure of the

 * document. <code>DocumentFragment</code> nodes do not need to be

 * well-formed XML documents (although they do need to follow the rules

 * imposed upon well-formed XML parsed entities, which can have multiple top

 * nodes).  For example, a <code>DocumentFragment</code> might have only one

 * child and that child node could be a <code>Text</code> node. Such a

 * structure model  represents neither an HTML document nor a well-formed XML

 * document.

 * <p>When a <code>DocumentFragment</code> is inserted into a

 * <code>Document</code> (or indeed any other <code>Node</code> that may take

 * children) the children of the <code>DocumentFragment</code> and not the

 * <code>DocumentFragment</code>  itself are inserted into the

 * <code>Node</code>. This makes the <code>DocumentFragment</code> very

 * useful when the user wishes to create nodes that are siblings; the

 * <code>DocumentFragment</code> acts as the parent of these nodes so that the

 *  user can use the standard methods from the <code>Node</code>  interface,

 * such as <code>insertBefore()</code> and  <code>appendChild()</code>.

 */

class DEPRECATED_DOM_EXPORT DOM_DocumentFragment: public DOM_Node {

public:

    /** @name Constructors and assignment operators */

    //@{

    /**

    * Default constructor for <code>DOM_DocumentFragment</code>.  The resulting object does not

    * refer to an actual Document Fragment node; it will compare == to 0, and is similar

    * to a null object reference variable in Java.  It may subsequently be

    * assigned to refer to an actual Document Fragment node.

    * <p>

    * New document fragment nodes are created by DOM_Document::createDocumentFragment().

    *

    */

    DOM_DocumentFragment();

    /**

      * Copy constructor.  Creates a new <code>DOM_DocumentFragment</code> that refers to the

      *   same underlying node as the original.  See also DOM_Node::clone(),

      * which will copy the actual Document fragment node, rather than just creating a new

      * reference to the original node.

      *

      * @param other The object to be copied

      */

    DOM_DocumentFragment(const DOM_DocumentFragment &other);

    /**

      * Assignment operator

      *

      * @param other The object to be copied

      */

    DOM_DocumentFragment & operator = (const DOM_DocumentFragment &other);

    /**

      * Assignment operator.  This overloaded variant is provided for

      *   the sole purpose of setting a DOM_Node reference variable to

      *   zero.  Nulling out a reference variable in this way will decrement

      *   the reference count on the underlying Node object that the variable

      *   formerly referenced.  This effect is normally obtained when reference

      *   variable goes out of scope, but zeroing them can be useful for

      *   global instances, or for local instances that will remain in scope

      *   for an extended time,  when the storage belonging to the underlying

      *   node needs to be reclaimed.

      *

      * @param val   Only a value of 0, or null, is allowed.

      */

    DOM_DocumentFragment & operator = (const DOM_NullPtr *val);

	//@}

    /** @name Destructor */

    //@{

    /**

      * Destructor.  The object being destroyed is the reference

      * object, not the underlying Comment node itself.

      *

      */

    ~DOM_DocumentFragment();

	//@}

protected:

    DOM_DocumentFragment(DocumentFragmentImpl *);

    friend class DOM_Document;

    friend class RangeImpl;

};

XERCES_CPP_NAMESPACE_END

#endif