How do I pass arguments to a TestStand sequence from an operator interface written in LabWindows​?

Question

I intend to use TS_EngineNewExecution() which takes a VARIANT parameter for the arguments.
I have only found example code for C++ where a propertyObject containing the arguments is converted to a VARIANT using the constructor of the _variant_t class.
How do I accomplish this in LabWindows?

Answer 1

Hi webprofile,
I did not extensively test this code, but based on the previous posts, this is what the function might look like (I bolded the changes from what ships by default):
TERetval Eng_BeginSeqExecution(tSeqFileRec *seqFileRec, // must NOT be NULL
                               tSeqRec *seqRec,            // must NOT be NULL
                               ListType checkedStepList,
                               TEBool breakAtFirstTest)
    HRESULT res = 0;
    ERRORINFO errorInfo;
    TEBool errorOccurred = FALSE;
    CAObjHandle newExeH = 0;
    VARIANT editArgsVar;
    CAObjHandle editArgsH = 0;
    CAObjHandle params = 0;
    LPDISPATCH dispPtr; // varible used to convert parameters from CAObjHandle to Variant
    // Create container that will hold two parameters. First parameter is a number, second is a string.
    oleErrChkReportErrInfo(TS_EngineNewPropertyObject (sTEEngineObj, &errorInfo, TS_PropValType_Container, VFALSE, "", 0,&params));
    TS_PropertySetValNumber (params, &errorInfo, "Param1", 1, 45);
    TS_PropertySetValString (params, &errorInfo, "Param2", 1, "This is a string");
    // Converts CAObjHandle to Dispatch pointer
    TERetChk(CA_GetDispatchFromObjHandle (params, &dispPtr));
    TERetChk(CreateEditArgsObj(0, seqFileRec->seqFileH, seqRec->seqH, checkedStepList, &editArgsH));
    if (editArgsH) {
        LPDISPATCH editArgsDispatch = NULL;
        CA_GetDispatchFromObjHandle (editArgsH, &editArgsDispatch);
        editArgsVar = CA_VariantDispatch(editArgsDispatch);
    } else
        editArgsVar = CA_DEFAULT_VAL;
    oleErrChkReportErrInfo(TS_EngineNewExecution (sTEEngineObj, &errorInfo,
                                                  seqFileRec->seqFileH,
                                                  seqRec->seqName, 0,
                                                  TEBool2VBOOL(breakAtFirstTest),
                                                  TS_ExecTypeMask_Normal,
                                                  CA_VariantDispatch(dispPtr),
                                                  editArgsVar,
                                                  CA_DEFAULT_VAL, &newExeH));
    /* we'll get this again later on the StartOfExecution event
     * so free this reference to it */
    CA_DiscardObjHandle(newExeH);
Error:
    if (editArgsH)
        CA_DiscardObjHandle(editArgsH);
    return !(errorOccurred || res < 0); /* return TRUE if no errors occurred */