This maybe heavier than you need, but it sounds like you are trying to make a frame work class that supports plugins.
I would break it up into to 3 sections.
1) The FrameWork class would own the plugins.
This class is responsable for publishing interfaces supplied by the plugins.
2) A PlugIn class would own the componets that do the work.
This class is responsable for registering the exported interfaces, and binding the imported interfaces to the components.
3) The third section, the componets are the suppliers and consumers of the interfaces.
To make things extensible, getting things up and running might be broke up into stages.
- Create everything.
- Wire everything up.
- Start everything.
To break things down.
- Stop everything.
- Destroy everything.
class IFrameWork {
public:
virtual ~IFrameWork() {}
virtual void RegisterInterface( const char*, void* ) = 0;
virtual void* GetInterface( const char* name ) = 0;
};
class IPlugIn {
public:
virtual ~IPlugIn() {}
virtual void BindInterfaces( IFrameWork* frameWork ) {};
virtual void Start() {};
virtual void Stop() {};
};
struct SamplePlugin :public IPlugIn {
ILogger* logger;
Component1 component1;
WebServer webServer;
public:
SamplePlugin( IFrameWork* frameWork )
:logger( (ILogger*)frameWork->GetInterface( "ILogger" ) ), //assumes the 'System' plugin exposes this
component1(),
webServer( component1 )
{
logger->Log( "MyPlugin Ctor()" );
frameWork->RegisterInterface( "ICustomerManager", dynamic_cast( &component1 ) );
frameWork->RegisterInterface( "IVendorManager", dynamic_cast( &component1 ) );
frameWork->RegisterInterface( "IAccountingManager", dynamic_cast( &webServer ) );
}
virtual void BindInterfaces( IFrameWork* frameWork ) {
logger->Log( "MyPlugin BindInterfaces()" );
IProductManager* productManager( static_cast( frameWork->GetInterface( "IProductManager" ) ) );
IShippingManager* shippingManager( static_cast( frameWork->GetInterface( "IShippingManager" ) ) );
component1.BindInterfaces( logger, productManager );
webServer.BindInterfaces( logger, productManager, shippingManager );
}
virtual void Start() {
logger->Log( "MyPlugin Start()" );
webServer.Start();
}
virtual void Stop() {
logger->Log( "MyPlugin Stop()" );
webServer.Stop();
}
};
class FrameWork :public IFrameWork {
vector plugIns;
map interfaces;
public:
virtual void RegisterInterface( const char* name, void* itfc ) {
interfaces[ name ] = itfc;
}
virtual void* GetInterface( const char* name ) {
return interfaces[ name ];
}
FrameWork() {
//Only interfaces in 'SystemPlugin' can be used by all methods of the other plugins
plugIns.push_back( new SystemPlugin( this ) );
plugIns.push_back( new SamplePlugin( this ) );
//add other plugIns here
for_each( plugIns.begin(), plugIns.end(), bind2nd( mem_fun( &IPlugIn::BindInterfaces ), this ) );
for_each( plugIns.begin(), plugIns.end(), mem_fun( &IPlugIn::Start ) );
}
~FrameWork() {
for_each( plugIns.rbegin(), plugIns.rend(), mem_fun( &IPlugIn::Stop ) );
for_each( plugIns.rbegin(), plugIns.rend(), Delete() );
}
};