/*
 * Copyright (c) 1999-2000, Eric Moon.
 * 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 name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND 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.
 */


// MessageIO.h
// * PURPOSE
//   Export/import of BMessages to and from
//   XML using the Cortex persistence library.
//   Messages are stored in a user-readable form.
//
//   TO DO +++++
//   - sanity-check string values (filter/escape single quotes)
//
// * HISTORY
//   e.moon             1dec99          Begun.

#ifndef __MessageIO_H__
#define __MessageIO_H__

#include <Message.h>
#include <String.h>
#include "XML.h"

#include "cortex_defs.h"
__BEGIN_CORTEX_NAMESPACE

class MessageIO :
        public          IPersistent {

public:                                                                                         // *** ctor/dtor/accessor
        virtual ~MessageIO();

        MessageIO(); //nyi
        
        // When given a message to export, this object does NOT take
        // responsibility for deleting it.  It will, however, handle
        // deletion of an imported BMessage.  
        
        MessageIO(
                const BMessage*                                         message);
        void setMessage(
                BMessage*                                                                       message);
        
        // Returns 0 if no message has been set, and if no message has
        // been imported.
        
        const BMessage* message() const { return m_message; }
        
        // Returns true if the message will be automatically deleted.
        
        bool ownsMessage() const { return m_ownMessage; }

public:                                                                                         // *** static setup method
        // call this method to install hooks for the tags needed by
        // MessageIO into the given document type
        static void AddTo(
                XML::DocumentType*                              docType);
        
public:                                                                                         // *** XML formatting
        static const char* const                s_element;

public:                                                                                         // *** IPersistent impl.

        // EXPORT:
        
        void xmlExportBegin(
                ExportContext&                                          context) const;
                
        void xmlExportAttributes(
                ExportContext&                                          context) const;
        
        void xmlExportContent(
                ExportContext&                                          context) const;
        
        void xmlExportEnd(
                ExportContext&                                          context) const;


        // IMPORT:

        virtual void xmlImportBegin(
                ImportContext&                                          context);

        virtual void xmlImportAttribute(
                const char*                                                             key,
                const char*                                                             value,
                ImportContext&                                          context);
        
        virtual void xmlImportContent(
                const char*                                                             data,
                uint32                                                                          length,
                ImportContext&                                          context);
        
        virtual void xmlImportChild(
                IPersistent*                                                    child,
                ImportContext&                                          context);
                        
        virtual void xmlImportComplete(
                ImportContext&                                          context);
                
        virtual void xmlImportChildBegin(
                const char*                                                             name,
                ImportContext&                                          context);

        virtual void xmlImportChildAttribute(
                const char*                                                             key,
                const char*                                                             value,
                ImportContext&                                          context);
        
        virtual void xmlImportChildContent(
                const char*                                                             data,
                uint32                                                                          length,
                ImportContext&                                          context);

        virtual void xmlImportChildComplete(
                const char*                                                             name,
                ImportContext&                                          context);

private:                                                                                        // *** members
        bool                                                                                            m_ownMessage;
        BMessage*                                                                               m_message;
        
        // name of the message (if used to import a nested BMessage)
        BString                                                                                 m_name;
        
        // current field
        BString                                                                                 m_fieldName;
        BString                                                                                 m_fieldData;
        
        bool _isValidMessageElement(
                const char*                                                             element) const;

        status_t _importField(
                BMessage*                                                                       message,
                const char*                                                             element,
                const char*                                                             name,
                const char*                                                             data);
                
        status_t _exportField(
                ExportContext&                                          context,
                BMessage*                                                                       message,
                type_code                                                                       type,
                const char*                                                             name,
                int32                                                                                   index) const;
};

__END_CORTEX_NAMESPACE

#endif /*__MessageIO_H__*/