External file for calculations

[Jeff Barnes]

Is there a way to have an external file (txt or maybe ini) where I could put code and have my app run that code and return a result?

I want to be able to give my users a way to change a formula that uses data in a dbf file.

Example of external file:

IF TEST->Age > 40
nResult := (TEST->Data1 * TEST->Data2) - (TEST->Data3 / TEST->Data4)
ELSE
nResult := (TEST->Data1 * TEST->Data2) - (TEST->Data3 / TEST->Data4) + 500
ENDIF

[ukoenig]

Jeff,

a Solution without using a extra File :

1. add a new Value-field to the DBF.
2. save the Value to the 1. physical Record. )
3. Before working with the DBF, go to the 1. Record ( Ordkeyno() because of maybe defined Index)
-- to read the Value for Your calculations.

Best Regards
Uwe

[Jeff Barnes]

Thanks for the reply Uwe but what I am looking to do is give the user the ability to create their own formulas.

[Enrico Maria Giordano]

Try this:

nResult := &( "(TEST->Data1 * TEST->Data2) - (TEST->Data3 / TEST->Data4)" )

EMG

[Armando]

Jeff:

Perhaps the Antonio's script.prg can help you.

viewtopic.php?f=6&t=21557&hilit=script&start=0

Or This one

http://www.xharbour.com/products/xbscript.php

Regards

[kok joek hoa]

Hi Jeff,

Here sample the function that I use to calculate using outside string.

Regards,

kok

Code: Select all  Expand view

*-- FUNCTION -----------------------------------------------------------------
* Name........: HITUNG_BERAT
* Description.:
* Parameters..:
* Return value: none
* Author......:
*-----------------------------------------------------------------------------
STATIC FUNCTION HITUNG_BERAT(cstring)

    LOCAL CRUMUS    :=ALLTRIM(cstring)
    LOCAL CTEMP     :=''
    LOCAL ARUMUS    :={}
    LOCAL NCTL      :=0

    LOCAL NTEBAL    :=0.000
    LOCAL NLEBAR    :=0.000
    LOCAL NPANJANG  :=0.000
    LOCAL NOD       :=0.000
    LOCAL NID       :=0.000
    LOCAL NILAI_KG  :=0.000

   
    if alltrim(crumus)==''
       return 0
    endif  
   
    
    FOR NCTL=1 TO LEN(CRUMUS)

        IF  SUBSTR(CRUMUS,NCTL,1)=='('  .OR. ;
            SUBSTR(CRUMUS,NCTL,1)==')'  .OR. ;
            SUBSTR(CRUMUS,NCTL,1)=='+'   .OR. ;
            SUBSTR(CRUMUS,NCTL,1)=='-'   .OR. ;
            SUBSTR(CRUMUS,NCTL,1)=='/'   .OR. ;
            SUBSTR(CRUMUS,NCTL,1)=='*'
            AADD(ARUMUS,SUBSTR(CRUMUS,NCTL,1) )
        elseIF ISALPHA(SUBSTR(CRUMUS,NCTL,1))
            IF ISALPHA(SUBSTR(CRUMUS,NCTL+1,1))
              AADD(ARUMUS, SUBSTR(CRUMUS,NCTL,2) )
              NCTL :=NCTL+1
            ELSE
              AADD(ARUMUS, SUBSTR(CRUMUS,NCTL,1) )
            ENDIF  
        else
             AADD(ARUMUS, SUBSTR(CRUMUS,NCTL,1) )      
        ENDIF
   
    NEXT
   

    FOR NCTL=1 TO LEN(ARUMUS)

        DO CASE
            CASE ARUMUS[NCTL] =='T'
               
                IF (AALIAS[DB_SATUAN])->(DBSEEK(ODATABASE[DB_UKURAN]:UTEBAL))     
                    IF    (AALIAS[DB_SATUAN])->TIPE
                        NTEBAL := ODATABASE[DB_UKURAN]:TEBAL * (AALIAS[DB_SATUAN])->KONVERSI
                    ENDIF
                ENDIF
               
                ARUMUS[NCTL] := NTEBAL
           
            CASE ARUMUS[NCTL] =='L'        
                IF (AALIAS[DB_SATUAN])->(DBSEEK(ODATABASE[DB_UKURAN]:ULEBAR))     
                    IF    (AALIAS[DB_SATUAN])->TIPE
                        NLEBAR := ODATABASE[DB_UKURAN]:LEBAR * (AALIAS[DB_SATUAN])->KONVERSI
                    ENDIF
                ENDIF        
                ARUMUS[NCTL] :=NLEBAR
               
            CASE ARUMUS[NCTL] =='P'        
                IF (AALIAS[DB_SATUAN])->(DBSEEK(ODATABASE[DB_UKURAN]:UPANJANG))   
                    IF    (AALIAS[DB_SATUAN])->TIPE
                        NPANJANG := ODATABASE[DB_UKURAN]:PANJANG * (AALIAS[DB_SATUAN])->KONVERSI
                    ENDIF
                ENDIF          
                ARUMUS[NCTL] := NPANJANG
               
            CASE ARUMUS[NCTL] =='OD'           
                IF (AALIAS[DB_SATUAN])->(DBSEEK(ODATABASE[DB_UKURAN]:UOD))     
                    IF    (AALIAS[DB_SATUAN])->TIPE
                        NOD := ODATABASE[DB_UKURAN]:OD * (AALIAS[DB_SATUAN])->KONVERSI
                    ENDIF
                ENDIF      
                ARUMUS[NCTL] :=NOD
               
            CASE ARUMUS[NCTL] =='ID'           
                IF (AALIAS[DB_SATUAN])->(DBSEEK(ODATABASE[DB_UKURAN]:UID))     
                    IF    (AALIAS[DB_SATUAN])->TIPE
                        NID := ODATABASE[DB_UKURAN]:ID * (AALIAS[DB_SATUAN])->KONVERSI
                    ENDIF
                ENDIF   
                ARUMUS[NCTL] :=NID
               
            CASE ARUMUS[NCTL] =='BJ'
                ARUMUS[NCTL] := VGET[VAR_VALUE_BERAT_JENIS]
            CASE ARUMUS[NCTL] =='PR'
                ARUMUS[NCTL] := VGET[VAR_VALUE_PARAMETER]
           
               
        ENDCASE    
     
    NEXT  

    FOR NCTL =1 TO LEN(ARUMUS)
         
        DO CASE
            CASE VALTYPE(ARUMUS[NCTL])<>'N'
                CTEMP := CTEMP + ARUMUS[NCTL]
            CASE VALTYPE(ARUMUS[NCTL])=='N'
                CTEMP := CTEMP+ALLTRIM(STR(ARUMUS[NCTL]))
        ENDCASE    
    NEXT

   
   
    NILAI_KG :=&(CTEMP)
   

   
    nilai_kg := nilai_kg    

RETURN NILAI_KG

[FiveWiDi]

Is there a way to have an external file (txt or maybe ini) where I could put code and have my app run that code and return a result?

I want to be able to give my users a way to change a formula that uses data in a dbf file.

Example of external file:

IF TEST->Age > 40
nResult := (TEST->Data1 * TEST->Data2) - (TEST->Data3 / TEST->Data4)
ELSE
nResult := (TEST->Data1 * TEST->Data2) - (TEST->Data3 / TEST->Data4) + 500
ENDIF

Jefff try tihis:

In your application:
/* ***************************************** */
FUNCTION ExeFile( )
Local cFile := "MyAMPA32.prg"
Local nRespuesta := 0

Local ureturn := Nil

If File (cFile )

If File ( "MyAMPA32.hrb" )
HB_HRBRun( "MyAMPA32.hrb", @ureturn )
Else
If (nRespuesta := HB_Compile( "", cFile, "-n", "-gh" ) ) == 0
HB_HRBRun( "MyAMPA32.hrb", @ureturn )
EndIf
EndIf

EndIf

msgalert( ureturn, "ssss" )

Return nRespuesta
/* ***************************************** */

Your external PRG:
/* ***************************************** */
FUNCTION MyAMPA32( uReturn )

uReturn := Date() + 5

RETURN uReturn - 3
/* ***************************************** */

If you changes the external file, you must delete the "MyAMPA32.hrb" file.

For this you must add the lib "hbcplr.lib"

Regards,

[Antonio Linares]

Jeff,

Please review FWH\samples\scripts.prg, it uses the powerful Harbour capability to have the full Harbour compiler inside your own apps so you can compile and run any external file with code or dinamically generated code from your app

In FWH 12.07 we provide a new function Execute( cCode, params ) --> uResult that simplifies the process,