ProSysLib: Dissecting the Process

/////////////////////////////////////////////////////////
// File PSLDeploy.h simplifies deployment of ProSysLib;
//
// Important:
//
// It does not use Windows Registry, i.e. the component
// does not need to be registered on the end-user PC.
/////////////////////////////////////////////////////////

#ifndef PSL_Deploy

#ifndef PSL_FILE
	#error "You must define PSL_FILE before including this file."
#endif

// Importing the type library...
#import PSL_FILE named_guids

class CPSLDeploy
{
	typedef ProSysLib::IPSLSystem * (WINAPI * CreatePSLSystemProc)();

public:

	CPSLDeploy()
	{
		m_hPSLModule = NULL;
		m_CreatePSLSystem = NULL;
	}

	bool Initialize(LPCTSTR sPSLFilePath)
	{
		if(m_hPSLModule)
			return false; // Must not call more than once;

		m_hPSLModule = ::LoadLibrary(sPSLFilePath);
		if(m_hPSLModule)
			m_CreatePSLSystem = (CreatePSLSystemProc)::GetProcAddress(m_hPSLModule, "CreatePSLSystem");

		return m_CreatePSLSystem != NULL;
	}

	virtual ~CPSLDeploy()
	{
		if(m_hPSLModule)
			::FreeLibrary(m_hPSLModule);
	}

	ProSysLib::IPSLSystem * CreateInstance()
	{
		if(m_CreatePSLSystem)
			return m_CreatePSLSystem();
		return NULL;
	}

private:

	HMODULE m_hPSLModule;
	CreatePSLSystemProc m_CreatePSLSystem;
};

#endif