DataSource.h

/*
╔══════════════════════════════════════════════════════════════════════════════╗
║                       SIMPLY POWERFUL TOOLKIT (SPTK)                         ║
╟──────────────────────────────────────────────────────────────────────────────╢
║  copyright            © 1999-2022 Alexey Parshin. All rights reserved.       ║
║  email                alexeyp@gmail.com                                      ║
╚══════════════════════════════════════════════════════════════════════════════╝
┌──────────────────────────────────────────────────────────────────────────────┐
│   This library is free software; you can redistribute it and/or modify it    │
│   under the terms of the GNU Library General Public License as published by  │
│   the Free Software Foundation; either version 2 of the License, or (at your │
│   option) any later version.                                                 │
│                                                                              │
│   This library 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 Library   │
│   General Public License for more details.                                   │
│                                                                              │
│   You should have received a copy of the GNU Library General Public License  │
│   along with this library; if not, write to the Free Software Foundation,    │
│   Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.               │
│                                                                              │
│   Please report all bugs and problems to alexeyp@gmail.com.                  │
└──────────────────────────────────────────────────────────────────────────────┘
*/
 
#pragma once
 
#include <sptk5/FieldList.h>
#include <sptk5/Variant.h>
 
class Fl_Group;
 
namespace sptk {
 
class SP_EXPORT DataSource
{
    friend class Fl_Group;
 
public:
    DataSource() = default;
 
    virtual ~DataSource() = default;
 
    virtual Field& operator[](size_t fieldIndex) = 0;
 
    virtual Field& operator[](const String& fieldName) = 0;
 
    virtual size_t fieldCount() const = 0;
 
    virtual size_t recordCount() const = 0;
 
    virtual bool readField(const char* fieldName, Variant& fieldValue) = 0;
 
    virtual bool writeField(const char* fieldName, const Variant& fieldValue) = 0;
 
    virtual bool open()
    {
        return false;
    }
 
    virtual bool close()
    {
        return false;
    }
 
    virtual bool first()
    {
        return false;
    }
 
    virtual bool next()
    {
        return false;
    }
 
    virtual bool prior()
    {
        return false;
    }
 
    virtual bool last()
    {
        return false;
    }
 
    virtual bool find(const String& /*fieldName*/, const Variant& /*position*/)
    {
        return false;
    }
 
    virtual bool eof() const
    {
        return false;
    }
 
    bool load();
 
    bool save();
 
    void exportRowTo(const xdoc::SNode& node, bool compactXmlMode, bool nullLargeData = false);
 
    virtual void exportTo(xdoc::Node& parentNode, const String& nodeName, bool compactXmlMode);
 
protected:
    virtual bool loadData()
    {
        return true;
    }
 
    virtual bool saveData()
    {
        return true;
    }
};
 
} // namespace sptk