//
// ConfigurationView.h
//
// $Id: //poco/Main/Util/include/Util/ConfigurationView.h#2 $
//
// Definition of the ConfigurationView class.
//
// Copyright (c) 2004-2005, Guenter Obiltschnig/Applied Informatics.
// 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. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
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//
// 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
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//


#ifndef Util_ConfigurationView_INCLUDED
#define Util_ConfigurationView_INCLUDED


#ifndef Util_Util_INCLUDED
#include "Util/Util.h"
#endif
#ifndef Util_AbstractConfiguration_INCLUDED
#include "Util/AbstractConfiguration.h"
#endif


Util_BEGIN


class Util_API ConfigurationView: public AbstractConfiguration
	/// This configuration implements a "view" into a sub-hierarchy 
	/// of another configuration.
	/// 
	/// For example, given a configuration with the following properties:
	///     config.value1
	///     config.value2
	///     config.sub.value1
	///     config.sub.value2
	/// and a ConfigurationView with the prefix "config", then
	/// the above properties will be available via the view as
	///     value1
	///     value2
	///     sub.value1
	///     sub.value2
	///
	/// A ConfigurationView is most useful in combination with a
	/// LayeredConfiguration.
{
public:
	ConfigurationView(const std::string& prefix, AbstractConfiguration* pConfig);
		/// Creates the ConfigurationView. The ConfigurationView does not take
		/// ownership of the passed configuration.

protected:
	bool getRaw(const std::string& key, std::string& value) const;
	void setRaw(const std::string& key, const std::string& value);
	void enumerate(const std::string& key, Keys& range) const;
	
	std::string translateKey(const std::string& key) const;
	
	~ConfigurationView();

private:
	ConfigurationView(const ConfigurationView&);
	ConfigurationView& operator = (const ConfigurationView&);

	std::string _prefix;
	AbstractConfiguration* _pConfig;
};


Util_END


#endif // Util_ConfigurationView_INCLUDED