Visual FoxPro 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. Visual FoxPro

LOCAL lnSuccess
LOCAL loFmt
LOCAL loJson
LOCAL loJsonOut

lnSuccess = 0

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

loFmt = CreateObject('Chilkat.Formats')
loJson = CreateObject('Chilkat.JsonObject')
loJsonOut = CreateObject('Chilkat.JsonObject')

*  1. A misspelled option: "moduleSise" for "moduleSize".
loJson.UpdateString("payload.text","https://www.chilkatsoft.com/")
loJson.UpdateInt("render.moduleSise",8)
lnSuccess = loFmt.QrCode("generate",loJson,loJsonOut)
IF (lnSuccess = 0) THEN
    ? "code: " + loJsonOut.StringOf("errors[0].code")
    ? "path: " + loJsonOut.StringOf("errors[0].path")
    ? "message: " + loJsonOut.StringOf("errors[0].message")
ENDIF

*  2. A value out of range: QR versions are 1 to 40.
loJson.Clear()
loJson.UpdateString("payload.text","https://www.chilkatsoft.com/")
loJson.UpdateInt("encoding.qr.version",41)
lnSuccess = loFmt.QrCode("generate",loJson,loJsonOut)
IF (lnSuccess = 0) THEN
    ? "code: " + loJsonOut.StringOf("errors[0].code")
    ? "path: " + loJsonOut.StringOf("errors[0].path")
    ? "message: " + loJsonOut.StringOf("errors[0].message")
ENDIF

*  3. Too much data: this text does not fit a version 1 symbol.
loJson.Clear()
loJson.UpdateString("payload.text","https://www.chilkatsoft.com/barcode_overview.asp")
loJson.UpdateInt("encoding.qr.version",1)
lnSuccess = loFmt.QrCode("generate",loJson,loJsonOut)
IF (lnSuccess = 0) THEN
    ? "code: " + loJsonOut.StringOf("errors[0].code")
    ? "path: " + loJsonOut.StringOf("errors[0].path")
    ? "message: " + loJsonOut.StringOf("errors[0].message")
ENDIF

*  A program can act on the code.
IF (loJsonOut.StringOf("errors[0].code") = "capacityExceeded") THEN
    ? "The text is too long for the symbol size allowed."
ENDIF

*  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.

RELEASE loFmt
RELEASE loJson
RELEASE loJsonOut