libclam-dev 1.4.0-7 / usr / include / CLAM / XMLIterableAdapter.hxx

/*
 * 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 XMLIterableAdapter
// 

#ifndef _XMLIterableAdapter_h
#define _XMLIterableAdapter_h

#include "BasicXMLable.hxx"
#include "XMLAdapter.hxx"
#include "XMLComponentAdapter.hxx"
#include "TypeInfo.hxx"
#include <sstream>
#include <iostream>


namespace CLAM {

/**
 * @ingroup XmlAdapters
 * @brief This class adapts to the XMLable interface any STL like container
 * of basic objects or CLAM::Component's.
 *
 * It supports both kind of subitems: Components and Basic Types.
 * Depending on the kind of subitem it calculates the XML content
 * with such extraction operator operator when subitems are basic objects
 * or it stores recursivelly when they are components.
 * The content is the same one which the insertion operator 
 * generates inserting an space between elements.
 * 
 * <P>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 CLAM::BasicXMLable).
 * 
 * @see XMLable
 * @see XMLAdapter
 * @see XMLComponentAdapter
 */
template <class T> class XMLIterableAdapter : public BasicXMLable , public Component {
// Internal Types
public:
	typedef BasicXMLable super;
	typedef T t_adaptee;
	typedef typename t_adaptee::value_type t_adapteeValues;
	typedef typename t_adaptee::iterator t_adapteeIterator;
	typedef typename TypeInfo<t_adapteeValues>::StorableAsLeaf BasicIsStorableAsLeaf;
// Attributes
private:
	t_adaptee & mAdaptee;
	const char * mElementsName;
// Construction/Destruction
public:
	/**
	 * Constructs a XMLIterableAdapter
	 * @param anAdaptee The object to be adapted (where the 
	 * XML content will be extracted from)
	 * @param elementName The XML tag that will be open
	 *        for every element on the iterable.
	 *        Only apliable when elements are not basics.
	 * @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.
	 */
	XMLIterableAdapter (T & anAdaptee, const char * elementName, const char * name=NULL, 
			bool isXMLElement=false)
		: BasicXMLable(name, isXMLElement), mAdaptee(anAdaptee)
	{
		mElementsName = elementName;
	}
	XMLIterableAdapter (const T & anAdaptee, const char * elementName, const char * name=NULL, 
			bool isXMLElement=false)
		: BasicXMLable(name, isXMLElement), mAdaptee(const_cast<T&>(anAdaptee))
	{
		mElementsName = elementName;
	}
	virtual ~XMLIterableAdapter() {};
	const char * GetClassName() const {
		CLAM_ASSERT(false, "You should never call XMLIterableAdapter::GetClassName");
		return 0;
	}

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

	//* Extracts the content from the stream.
	bool XMLContent(std::istream & str) 
	{
		return ContentLeaveOrComponent((BasicIsStorableAsLeaf*)NULL, str);
	}

// Operators (for Component interface)
public:
	/** 
	 * Stores subitems on the given Storage
	 * @param store The given storage where the subitem will be stored
	 * @see Storage
	 */
	virtual void StoreOn (Storage & store) const
	{
		StoreLeaveOrComponent (store, (BasicIsStorableAsLeaf*)NULL);
	};
	/**
	 * Loads component's subitems from the given Storage
	 * @param store The given storage where the subitem will be loaded from
	 * @todo Not yet implemented
	 * @see Storage
	 */
	virtual void LoadFrom (Storage & store) {
		mAdaptee.clear();
		while (true) {
			t_adapteeValues elem;
			if (!LoadLeaveOrComponent(store, elem,
						(BasicIsStorableAsLeaf *)NULL)
					)
				break;
			mAdaptee.push_back(elem);
		}
	};
// Implementation:
private:
	void StoreLeaveOrComponent (Storage& store, StaticTrue* isLeave) const 
	{
		t_adapteeIterator it=mAdaptee.begin();
		t_adapteeIterator end=mAdaptee.end();
		const char * separator = "";
		std::stringstream stream;
		for (; it!=end; it++) {
			stream << separator << *it;
			separator = " ";
		}
		std::string content=stream.str();
		XMLAdapter<std::string> adapter(content);
		store.Store(adapter);
	}
	void StoreLeaveOrComponent (Storage& store, StaticFalse* isLeave) const
	{
		t_adapteeIterator it=mAdaptee.begin();
		t_adapteeIterator end=mAdaptee.end();
		for (; it!=end; it++) {
			XMLComponentAdapter adapter(*it,mElementsName,true);
			store.Store(adapter);
		}
	}
	bool LoadLeaveOrComponent (Storage& store, t_adapteeValues & value, StaticTrue* isLeave) 
	{
		XMLAdapter<t_adapteeValues> adapter(value);
		return store.Load(adapter);
	}
	bool LoadLeaveOrComponent (Storage& store, t_adapteeValues & value, StaticFalse* isLeave)
	{
		XMLComponentAdapter adapter(value,mElementsName,true);
		return store.Load(adapter);
	}
	//* @return A string with the extracted XML content */
	std::string ContentLeaveOrComponent(StaticFalse* /*isLeave*/) const
	{
		return "";
	}
	/** @return A string with the extracted XML content */
	std::string ContentLeaveOrComponent(StaticTrue* /*isLeave*/) const
	{
		if (!IsXMLAttribute()) return "";
		std::stringstream stream;
		t_adapteeIterator it=mAdaptee.begin();
		t_adapteeIterator end=mAdaptee.end();
		bool first = true;
		for (; it!=end; it++) {
			if (first) first=false;
			else stream << " ";
			stream << *it;
		}
		return stream.str();
	}
	/**
	 * @todo Not yet implemented
	 */
	bool ContentLeaveOrComponent(StaticFalse* isLeave, std::istream &is) 
	{
		return true;
	}
	/**
	 * @todo Not yet implemented
	 */
	bool ContentLeaveOrComponent(StaticTrue* isLeave, std::istream &str) 
	{
		if (!IsXMLAttribute()) return true;
		mAdaptee.clear();
		while (str) {
			t_adapteeValues contained;
			str >> contained;
			if (str) mAdaptee.push_back(contained);
		}
		return true;
	}
// Testing
public:
	/// Check the internal status for a class instance is valid
	bool FulfilsInvariant();
};


// Check the internal status for a class instance is valid
template <class T>
bool XMLIterableAdapter<T>::FulfilsInvariant() 
{
	return super::FulfilsInvariant();
};

}

#endif//_XMLIterableAdapter_h