DataFlex

Check if Integer Exists at JSON Path

Demonstrates how to get an integer value at a JSON path, and how to check to see if it exists. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoJson
    String sPath
    Integer iVal
    Boolean iWasFound
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    Move False To iSuccess

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End

    // First build simple JSON..
    Get ComUpdateInt Of hoJson "test.abc" 100 To iSuccess

    Set ComEmitCompact Of hoJson To False
    Get ComEmit Of hoJson To sTemp1
    Showln sTemp1

    // This is our JSON:
    // {
    //   "test": {
    //     "abc": 100,
    //   }
    // }

    Move "test.notHere" To sPath

    // The call to IntOf will return 0, because it's not present.
    // But how do we know if it really was present, and the value was truly 0?
    Get ComIntOf Of hoJson sPath To iVal
    Showln "val = " iVal

    // We cannot use LastMethodSuccess because LastMethodSuccess only applies
    // to methods that:
    // - return a string
    // - return a new Chilkat object, binary bytes, or a date/time.
    // - returns a boolean status where True = success and False = failed.
    // - returns an integer where failure is defined by a return value less than zero.
    // The IntOf method fits none of these requirements, and therefore the LastMethodSuccess 
    // is not a valid indicator..
    Get ComLastMethodSuccess Of hoJson To iWasFound
    Showln "wasFound = " iWasFound " (not a valid indicator)"

    // Instead, if the returned value is 0, we can double-check to see if the member was truly there..
    If (iVal = 0) Begin
        Get ComHasMember Of hoJson sPath To iWasFound
        Showln "wasFound = " iWasFound
        If (iWasFound = True) Begin
            Showln "The value was present and is 0."
        End
        Else Begin
            Showln "no member is present at test.notHere"
        End

    End
    Else Begin
        Showln "val = " iVal
    End

    // Alternatively, you could check to see if the member exists beforehand..
    Get ComHasMember Of hoJson sPath To bTemp1
    If (bTemp1 = True) Begin
        Get ComIntOf Of hoJson sPath To iTemp1
        Showln "val = " iTemp1
    End
    Else Begin
        Showln "no member at " sPath
    End



End_Procedure