HOWTO: Get History Using SourceSafe OLE Automation in C++

• Microsoft Visual SourceSafe, 32-bit, for Windows, version 5.0

SUMMARY

The sample code in this article, along with the description of the structures and functions used, provides a guide to retrieving a collection of SourceSafe items and getting the history for these items. The sample code is written in C++.

MORE INFORMATION

The SourceSafe Object Model contains 7 objects. The top-most of these objects is the VSSDatabase object. The first step in any SourceSafe OLE Automation client is to make a connection to a VSSDatabase pointer through the IClassFactory interface. This article assumes that there is already a pointer to the VSSDatabase object. For more information about getting a VSSDatabase pointer, please see the following Knowledge Base article:

   ARTICLE-ID: Q169928
   TITLE     : HOWTO: Open a SourceSafe Database with OLE Automation in C++

The method discussed in this article is the Versions method, which returns a collection of Version objects. These represent old versions, labels and other actions that have been applied to the file or project in SourceSafe during its lifetime.

Once you have a pointer to a valid IVSSItem, call the get_Versions method. get_Versions requires a long integer containing a number representing flag values, and a pointer to a pointer to an IVSSVersions object.

Call the _NewEnum method from pointer to IVSSVersions passing a pointer to an LPUNKNOWN. Then QueryInterface on the LPUNKNOWN for an IEnumVARIANT interface. The IEnumVARIANT Interface supports Next, Skip, and Reset methods. Using the Next Method within a while loop allows you to retrieve each version within the collection using the punkVal property to get a pointer to IUnknown.

Sample Code

The following sample code illustrates this:

   #include <windows.h>
   #include <ocidl.h>
   #include <stdio.h>
   #include "ssauto.h"
   void ListVersions( IVSSDatabase* db, LPCSTR path )
   {
     BSTR bstrval;
     char lpbuf[200];
     char lpbuf2[200];

     IVSSItem     *vssi;
     IVSSVersion  *vers;
     IVSSVersions *vx;
     LPUNKNOWN    lpunk;
     IEnumVARIANT *ppvobj;
     VARIANT      st;
     OLECHAR*     svalue;
     BSTR         bstrValue;
     int          x;
     ULONG        fetched;
     long         lvnum;


     if( (x = MultiByteToWideChar(CP_ACP, 0, path, -1, svalue, 0 )) != 1)
     {
       svalue = new OLECHAR[x];
       if( MultiByteToWideChar(CP_ACP, 0, path, -1, svalue, x ) == 0 )
         MessageBox(NULL, "Error in Conversion", "Multibytetowide", MB_OK);
     }
     else
       svalue = L"";

     bstrValue = SysAllocString(svalue);

     if( S_OK == db->get_VSSItem(bstrValue, FALSE, &vssi) )
     {
       if( S_OK == vssi->get_Versions( 0l, &vx ) )
       {
         if( S_OK == vx->_NewEnum(&lpunk) )
         {
           if(!FAILED(lpunk->
             QueryInterface(IID_IEnumVARIANT, (void**)&ppvobj)))
           {
             vssi->get_Spec( &bstrval );
             x = WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)bstrval, -1,
               lpbuf, sizeof(lpbuf), NULL, NULL );
             printf("History of: %s\n", lpbuf );
             printf("ACTION   USER NAME   VERSION NUMBER\n");

             do
             {
               ppvobj->Next( 1UL, &st, &fetched );
               if( fetched != 0 )
               {
                 if(!FAILED(st.punkVal->
                   QueryInterface(IID_IVSSVersion,(void**)&vers)))
                 {
                   vers->get_Action( &bstrval );
                   WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)bstrval, -1,
                     lpbuf, sizeof(lpbuf), NULL, NULL );
                   vers->get_Username( &bstrval );
                   WideCharToMultiByte( CP_ACP, 0, (LPCWSTR)bstrval, -1,
                     lpbuf2, sizeof( lpbuf2 ), NULL, NULL );
                   vers->get_VersionNumber( &lvnum );
                   printf("%s  %s  %ld\n", lpbuf, lpbuf2, lvnum );

                   vers->Release();
                 }
                 st.punkVal->Release();
               }
             } while( fetched != 0 );
             ppvobj->Release();
           }
           lpunk->Release();
         }
         vx->Release();
       }
       vssi->Release();
     }
     SysFreeString(bstrValue);
   }

REFERENCES

TITLE: IClassFactory

  URL: mk:@ivt:pdobj/native/activex/src/if_a2e_68.htm

  URL: mk:@ivt:pdobj/native/sdk/ole/auto/src/chap5_18.htm

  URL: http://www.microsoft.com/SSAFE/download/oleauto.doc