DataFlex Requires Chilkat v11.7.0+

Handle QR Code Errors

See more QR Code Examples

Demonstrates what happens when a request is refused. QrCode returns false and the response holds errors[0] with three members: a code that does not change between versions, the path of the request member at fault (a JSON Pointer such as /encoding/qr/version), and a message. Requests are checked strictly, so a misspelled option is an error rather than being silently ignored. LastErrorText has the same information in more detail. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoFmt
    Variant vJson
    Handle hoJson
    Variant vJsonOut
    Handle hoJsonOut
    String sTemp1

    Move False To iSuccess

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

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

    //  1. A misspelled option: "moduleSise" for "moduleSize".
    Get ComUpdateString Of hoJson "payload.text" "https://www.chilkatsoft.com/" To iSuccess
    Get ComUpdateInt Of hoJson "render.moduleSise" 8 To iSuccess
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "generate" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComStringOf Of hoJsonOut "errors[0].code" To sTemp1
        Showln "code: " sTemp1
        Get ComStringOf Of hoJsonOut "errors[0].path" To sTemp1
        Showln "path: " sTemp1
        Get ComStringOf Of hoJsonOut "errors[0].message" To sTemp1
        Showln "message: " sTemp1
    End

    //  2. A value out of range: QR versions are 1 to 40.
    Send ComClear To hoJson
    Get ComUpdateString Of hoJson "payload.text" "https://www.chilkatsoft.com/" To iSuccess
    Get ComUpdateInt Of hoJson "encoding.qr.version" 41 To iSuccess
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "generate" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComStringOf Of hoJsonOut "errors[0].code" To sTemp1
        Showln "code: " sTemp1
        Get ComStringOf Of hoJsonOut "errors[0].path" To sTemp1
        Showln "path: " sTemp1
        Get ComStringOf Of hoJsonOut "errors[0].message" To sTemp1
        Showln "message: " sTemp1
    End

    //  3. Too much data: this text does not fit a version 1 symbol.
    Send ComClear To hoJson
    Get ComUpdateString Of hoJson "payload.text" "https://www.chilkatsoft.com/barcode_overview.asp" To iSuccess
    Get ComUpdateInt Of hoJson "encoding.qr.version" 1 To iSuccess
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "generate" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComStringOf Of hoJsonOut "errors[0].code" To sTemp1
        Showln "code: " sTemp1
        Get ComStringOf Of hoJsonOut "errors[0].path" To sTemp1
        Showln "path: " sTemp1
        Get ComStringOf Of hoJsonOut "errors[0].message" To sTemp1
        Showln "message: " sTemp1
    End

    //  A program can act on the code.
    Get ComStringOf Of hoJsonOut "errors[0].code" To sTemp1
    If (sTemp1 = "capacityExceeded") Begin
        Showln "The text is too long for the symbol size allowed."
    End

    //  Sample output:

    //  code: unknownOption
    //  path: /render/moduleSise
    //  message: unknown option
    //  code: outOfRange
    //  path: /encoding/qr/version
    //  message: the value is out of range
    //  code: capacityExceeded
    //  path: /payload
    //  message: the payload does not fit the requested QR version at the requested error-correction level
    //  The text is too long for the symbol size allowed.


End_Procedure