/*
 * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

//////////////////////////////////////////////////////////////////////
// Class XMLAdapter
// 

#ifndef _XMLAdapter_
#define _XMLAdapter_

#include "BasicXMLable.hxx"
#include <sstream>
#include <string>

namespace CLAM {

/**
 * @ingroup XmlAdapters
 * @brief This class adapts to the Storable interface any basic object.
 *
 * A basic object is that one that has
 * the insertion (<<) and extractor (>>) operators defined to streams
 * and there exists a TypeInfo struct for it (see CLAM_TYPE_INFO_GROUP).
 * The adapter uses such operators to calculate the XML content on writing
 * and reconstruct the object on reading.
 * 
 * During the construction, the adapter stores a reference to
 * the adaptee. The content string extracted on demand when the
 * adapter is stored on a XMLStorage, so the adapter is sensitive
 * to the adaptee changes after the construction. 
 *
 * <B>Important:</B> At storage time, the adaptee must exist in
 * order to follow the reference.
 *
 * <B>Pay attention to the management of the name memory</B>
 * @see BasicXMLable
 * @see Storable
 */
template <class T> class XMLAdapter : public BasicXMLable {
// Internal Types
public:
	typedef BasicXMLable super;
	typedef T t_adaptee;
// Attributes
private:
	t_adaptee & mAdaptee;
// Construction/Destruction
public:
	/**
	 * Constructs a XMLAdapter
	 * @param anAdaptee The object to be adapted (where the 
	 * XML content will be extracted from)
	 * @param name A pointer to a 0 terminated string 
	 * containing the xml name (for elements and attributes)
	 * or 0 (the default) if the element is neither an 
	 * element nor an attribute (@see #BasicXMLable for
	 * important details about memory managing).
	 * <B>Because no internal copy of the string is done, the 
	 * 0 terminated string pointed by <EM>name</EM> must 
	 * exist during the BasicXMLable life as is directly used.</B>
	 * @param isXMLElement Tells whether the object is an
	 * element or an attribute when the name is defined.
	 */
	XMLAdapter (t_adaptee & anAdaptee, const char * name=NULL, bool isXMLElement=false)
		: BasicXMLable(name, isXMLElement), mAdaptee(anAdaptee)
	{
	}
	XMLAdapter (const t_adaptee & anAdaptee, const char * name=NULL, bool isXMLElement=false)
		: BasicXMLable(name, isXMLElement), mAdaptee(const_cast<T&>(anAdaptee))
	{
	}
	virtual ~XMLAdapter() 
	{
	};

// Accessors
public:
	//* @return A string with the extracted XML content
	std::string XMLContent() const
	{

		std::stringstream str;
		str << mAdaptee << std::ends;
		return str.str();
	}

	//* Extracts the content from the stream.
	bool XMLContent(std::istream & str) 
	{
		str >> mAdaptee;
		return str!=NULL;
	}
// Testing
public:
	//* Check the internal status for a class instance is valid
	bool FulfilsInvariant()
	{
		return super::FulfilsInvariant();
	}
};

}
#endif//_XMLAdapter_

