|  |  |  | Libbonobo Reference Manual |  | 
|---|---|---|---|---|
| Top | Description | Object Hierarchy | ||||
                    BonoboMonikerExtender;
                    BonoboMonikerExtenderClass;
Bonobo_Unknown      (*BonoboMonikerExtenderFn)          (BonoboMonikerExtender *extender,
                                                         const Bonobo_Moniker parent,
                                                         const Bonobo_ResolveOptions *options,
                                                         const CORBA_char *display_name,
                                                         const CORBA_char *requested_interface,
                                                         CORBA_Environment *ev);
BonoboMonikerExtender * bonobo_moniker_extender_new     (BonoboMonikerExtenderFn resolve,
                                                         gpointer data);
Bonobo_MonikerExtender  bonobo_moniker_find_extender    (const gchar *name,
                                                         const gchar *interface,
                                                         CORBA_Environment *opt_ev);
Bonobo_Unknown      bonobo_moniker_use_extender         (const gchar *extender_oafiid,
                                                         BonoboMoniker *moniker,
                                                         const Bonobo_ResolveOptions *options,
                                                         const CORBA_char *requested_interface,
                                                         CORBA_Environment *opt_ev);
A moniker extender is used to extend the functionality of a moniker. There are two standard moniker extenders that cannot be system wide, since they use the oaf database to expand the scope of a moniker to arbitrarily many interfaces. These are invoked explicitely by monikers implementing the stream interface in the following way:
Example 18. Explicit Stream extender usage example
Bonobo_Unknown
example_moniker_resolve (BonoboMoniker               *moniker,
			 const Bonobo_ResolveOptions *options,
			 const CORBA_char            *requested_interface,
			 CORBA_Environment           *ev)
{
	if (!strcmp (requested_interface, "IDL:Bonobo/Stream:1.0"))
		return handle_stream (moniker, options, ev);
	else
		return bonobo_moniker_use_extender (
			"OAFIID:Bonobo_MonikerExtender_stream",
			moniker, options, requested_interface, ev);
}
     
  The moniker extender essentialy resolves 'moniker' against stream
and by some means ( not known when the moniker was written ) converts
this to a new exotic interface - via. the PersistStream interface.
All standard moniker extenders are registered by adding a fragment like this:
Example 19. Oaf information for an extender
<oaf_attribute name="bonobo:moniker_extender" type="stringv">
	<item value="file:"/>
</oaf_attribute>
    
to the .oaf file. This registers the extender with the system, such
that when a moniker resolve fails an extender can be found for any
of the monikers with prefix specified in the "bonobo:moniker_extender"
stringv.
Implementing your own extender is extremely simple, much like BonoboMonikerSimple.
Example 20. Oaf information for an extender
Bonobo_Unknown
example_extender_resolve (BonoboMonikerExtender *extender,
			  const Bonobo_Moniker   m,
			  const Bonobo_ResolveOptions *options,
			  const CORBA_char      *display_name,
			  const CORBA_char      *requested_interface,
			  CORBA_Environment     *ev)
{
	... resolve 'm' against an interface we know it supports ...
	... then use that interface to provide requested_interface ...
}
    
It is registered again in much the same way in your factory:
  
Example 21. Creating a new simple moniker
static BonoboObject *
bonobo_std_moniker_factory (BonoboGenericFactory *this,
			    const char           *object_id,
			    void                 *data)
{
	g_return_val_if_fail (object_id != NULL, NULL);
	if (!strcmp (object_id, "OAFIID:Bonobo_MonikerExtender_file"))
		return BONOBO_OBJECT (bonobo_moniker_extender_new (
			example_extender_resolve, NULL));
	else
		return NULL;
}
    
typedef struct _BonoboMonikerExtender BonoboMonikerExtender;
Implements a moniker extender: Bonobo::MonikerExtender.
typedef struct {
	BonoboObjectClass      parent_class;
	POA_Bonobo_MonikerExtender__epv epv;
	
	BonoboMonikerExtenderFn resolve;
} BonoboMonikerExtenderClass;
BonoboMonikerExtender's class.
Bonobo_Unknown (*BonoboMonikerExtenderFn) (BonoboMonikerExtender *extender, const Bonobo_Moniker parent, const Bonobo_ResolveOptions *options, const CORBA_char *display_name, const CORBA_char *requested_interface, CORBA_Environment *ev);
Moniker resolution callback function.
| 
 | extender (self) | 
| 
 | parent moniker | 
| 
 | resolve options | 
| 
 | ? FIXME | 
| 
 | ? FIXME | 
| 
 | |
| Returns : | the resolution resulting object | 
BonoboMonikerExtender * bonobo_moniker_extender_new (BonoboMonikerExtenderFn resolve, gpointer data);
This creates a new moniker extender.
| 
 | the resolve function that will be used to do the extension | 
| 
 | user data to be passed back to the resolve function. | 
| Returns : | the extender object | 
Bonobo_MonikerExtender bonobo_moniker_find_extender (const gchar *name, const gchar *interface, CORBA_Environment *opt_ev);
This routine tries to locate an extender for our moniker by examining a registry of extenders that map new interfaces to certain moniker names.
| 
 | the name of the moniker we want to extend eg. 'file:' | 
| 
 | the interface we want to resolve to | 
| 
 | an optional corba exception environment. | 
| Returns : | an appropriate extender or CORBA_OBJECT_NIL. | 
Bonobo_Unknown bonobo_moniker_use_extender (const gchar *extender_oafiid, BonoboMoniker *moniker, const Bonobo_ResolveOptions *options, const CORBA_char *requested_interface, CORBA_Environment *opt_ev);
Locates a known extender via. OAFIID; eg. OAFIID:Bonobo_Moniker_Extender_file
| 
 | The IID of the extender to use | 
| 
 | the moniker to extend | 
| 
 | resolve options | 
| 
 | the requested interface | 
| 
 | optional corba environment | 
| Returns : | the resolved result or CORBA_OBJECT_NIL. |