include/wvmoniker.h

/* -*- Mode: C++ -*-
 * Worldvisions Weaver Software:
 *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
 * 
 * Support for monikers, which are strings that you can pass to a magic
 * factory to get objects supporting a particular interface, without actually
 * knowing anything about the constructor for those objects.
 */
#ifndef __WVMONIKER_H
#define __WVMONIKER_H
 
#include "wvstring.h"
#include "wvxplc.h"
 
class WvMonikerRegistry;
 
typedef void *WvMonikerCreateFunc(WvStringParm parms, IObject *obj);

class WvMonikerBase
{
protected:
    WvMonikerBase(const UUID &iid, WvStringParm _id,
                  WvMonikerCreateFunc *func, const bool override = false);
    ~WvMonikerBase();
    
public:
    WvString id;
    WvMonikerRegistry *reg;
};
 

template <class T>
class WvMoniker : public WvMonikerBase
{
public:
    typedef T *CreateFunc(WvStringParm parms, IObject *obj);
    
    WvMoniker(WvStringParm _id, CreateFunc *_func, const bool override = false)
        : WvMonikerBase(XPLC_IID<T>::get(), _id, (WvMonikerCreateFunc *)_func,
                        override)
    { 
        // this looks pointless, but it ensures that T* can be safely,
        // automatically downcast to IObject*.  That means T is really derived
        // from IObject, which is very important. The 'for' avoids a
        // warning.
        for(IObject *silly = (T *)NULL; silly; )
            ;
    };
};
 

void *wvcreate(const UUID &iid, WvStringParm s, IObject *obj);
 

template <class T>
inline T *wvcreate(WvStringParm s, IObject *obj = 0)
{
    return (T *)(wvcreate(XPLC_IID<T>::get(), s, obj));
}
 
 
#endif // __WVMONIKER_H