String Handling in XPCOM

// xpcom_client.cpp : Defines the entry point for the console application.
//

	#include "stdafx.h"
	#include "nsCOMPtr.h"
	#include "nsXPCOMStrings.h"
	#include "nsXPCOM.h"
	#include "../sample_xpcom/ISample.h"
	#include "../sample_xpcom/Sample.h"
	#include "nsServiceManagerUtils.h"
	#include "nsStringAPI.h"


	int _tmain(int argc, _TCHAR* argv[])
	{
		nsresult rv;

		nsCOMPtr<nsIServiceManager> servMan;

		// Get Service manager
		rv = NS_GetServiceManager(getter_AddRefs(servMan));
		if (NS_FAILED(rv))
		{
			printf("ERROR: XPCOM error [%x].\n", rv);
			return -1;
		}

		// Get the Component object;
		nsCOMPtr<ISample> iSample;
		rv = servMan->GetServiceByContractID(SAMPLE_COMPONENT_CONTRACTID, NS_GET_IID(ISample), getter_AddRefs(iSample));	
		
		// Or you can get like this
		//rv = servMan->GetService(NS_GET_IID(CSample), NS_GET_IID(ISample), getter_AddRefs(iSample));
		
		
		if ( NS_FAILED(rv) )
		{
			NS_ShutdownXPCOM(nsnull);
			return -1;
		}

		int nFirstVal, nSecondVal, nResult;
		nFirstVal= 15; 
		nSecondVal = 10;
		iSample->Add(nFirstVal, nSecondVal, &nResult);

		_tprintf(_T("\nThe Result is : %d\n"), nResult);


		//---------------------------------------------------------------
		//----------------------- Using String types --------------------
		//---------------------------------------------------------------



		// IDL type		C++ Type		Purpose
		// string	    char*			Raw character pointer to ASCII (7-bit) string, no string classes used. High bit is not guaranteed across XPConnect boundaries.

		char chMainStr[256] = {'\0'};
		char *chRevStr;
		strcpy(chMainStr, "Test string");
		iSample->ReverseString(chMainStr, (char**)&chRevStr);
		printf("\nThe Main String: %s  The Reverted String : %s.\n", chMainStr, chRevStr);


		//	IDL type		C++ Type		Purpose
		//	wstring			PRUnichar*		Raw character pointer to UTF-16 string, no string classes used.

		wchar_t wchMainStr[256] = {'\0'};
		wchar_t *wchRevStr;	

		wcscpy(wchMainStr, L"Test wstring");
		iSample->ReverseUnichar(wchMainStr, &wchRevStr);
		wprintf(L"\nThe Main String: %s  The Reverted String : %s.\n", wchMainStr, wchRevStr);


		// IDL type			C++ Type		Purpose
		// AString			nsAString		UTF-16 string.
		nsString nsStringRev;
		nsString nsStringMain(L"Test AString");
		wcscpy(wchMainStr, nsStringMain.get());
		
		iSample->ReverseAString(nsStringMain, nsStringRev);
		
		wcscpy(wchRevStr, nsStringRev.get());

		wprintf(L"\nThe Main String: %s  The Reverted String : %s.\n", wchMainStr, wchRevStr);


		// IDL type			C++ Type		Purpose
		// ACString			nsACString		8-bit string. All bits are preserved across XPConnect boundaries.
		nsCString nsCStringRev;
		nsCString nsCStringMain("Test ACString");
		strcpy(chMainStr, nsCStringMain.get());
		iSample->ReverseACString(nsCStringMain, nsCStringRev);
		strcpy(chRevStr, nsCStringRev.get());
		
		printf("\nThe Main String: %s  The Reverted String : %s.\n", chMainStr, chRevStr);

		// Shutdown Service manager 
		NS_ShutdownXPCOM(nsnull);
		
		return 0;
	}