Executing APG Scripts in C++

Include File

To run APG scripts in C++, the APGen.h file must be included. It can normally be found at <install dir>/include/APGen.h. For insight into the Automation interfaces that are used in APGen, see <install dir>/include/APGen.idl.

Example

Below is a C++ example that executes an APG script. This code can be cut and pasted into your own applications.

/*
**     apgen_cpp.cpp
**
**     WebGecko Software
**
**     A simple C++ console app that executes an APG script.
**
**     The APG script's path is passed in the cmd line.
*/

#include <stdio.h>     // printf
#include <atlbase.h>   // ATL base include

// Include APGen COM definitions
#include "c:/Program Files/APGen/include/APGen.h"

/*--------------------------------------------------------------+
|     GetErrorInfoDescription                                   |
|                                                               |
|     Retrieves the description of the last COM error in this   |
|     thread, using the IErrorInfo object.                      |
+--------------------------------------------------------------*/

HRESULT GetErrorInfoDescription(LPWSTR wszErr, DWORD cchErr)
     {
     HRESULT hr;

     // Retrieve the IErrorInfo object for the current thread
     CComPtr<IErrorInfo> xpei;
     hr = ::GetErrorInfo(0, &xpei);

     if (FAILED(hr) ||
          !xpei)
          { // This does happen.  When no ErrorInfo is set, hr = S_FALSE and xpei = 0.
          ::lstrcpynW(wszErr, L"Error description not available.", cchErr);
          return S_FALSE;
          }

     // Copy the error description
     CComBSTR bstrDesc;
     xpei->GetDescription(&bstrDesc);
     ::lstrcpynW(wszErr, bstrDesc, cchErr);

     return S_OK;
     }

/*--------------------------------------------------------------+
|     main                                                      |
|                                                               |
|     Runs an APG script.  APGen.Run() could have been used in  |
|     place of APGen.OpenScript() and APGScript.Run().  However,|
|     using APGen.OpenScript() provides a better foundation for |
|     user modification.                                        |
+--------------------------------------------------------------*/

int main(int argc, char* argv[])
     {
     if ((argc < 2) || (argc > 2))
          {
          printf("Usage: apgen_cpp <APG script path>\r\n");
          return -1;
          }

     // Copy the script path to a BSTR
     CComBSTR bstrPath(argv[1]);

     // Declare variables
     HRESULT hr = S_OK;
     CComPtr<IAPGen> xpAPGen;
     CComPtr<IAPGScript> xpScript;

     // Error buffer
#define SIZE_ERRBUF 512
     WCHAR wszErr[SIZE_ERRBUF]; // Unicode buffer
     wszErr[0] = 0;

     // Initialize COM
     ::CoInitialize(0);

     // Create the Active Page Generator object
     hr = ::CoCreateInstance(__uuidof(APGen), 0, CLSCTX_INPROC_SERVER,
                                   __uuidof(IAPGen), (void**)&xpAPGen);
     if (FAILED(hr))
          {
          ::lstrcpyW(wszErr, L"Unable to create APGen object.  Try reinstalling Active Page Generator.");
          goto lError;
          }

     // Open the APG script
     hr = xpAPGen->OpenScript(bstrPath, &xpScript);
     if (FAILED(hr))
          {
          ::GetErrorInfoDescription(wszErr, SIZE_ERRBUF);
          goto lError;
          }

     // Set Debug = True
     xpScript->put_Debug(VARIANT_TRUE);

     // Run the script
     hr = xpScript->Run();
     if (FAILED(hr))
          {
          ::GetErrorInfoDescription(wszErr, SIZE_ERRBUF);
          goto lError;
          }

lCleanup:
     // Release COM objects
     xpScript.Release();
     xpAPGen.Release();

     // Uninitialize COM
     ::CoUninitialize();

     return hr; // 0 if no errors

lError:
     ::printf("Error running APG script '%S':\r\n\t%S", bstrPath, wszErr);
     goto lCleanup;
     }