Xojo Plugin 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. Xojo Plugin

Dim success As Boolean
success = False

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

Dim fmt As New Chilkat.Formats
Dim json As New Chilkat.JsonObject
Dim jsonOut As New Chilkat.JsonObject

//  1. A misspelled option: "moduleSise" for "moduleSize".
success = json.UpdateString("payload.text","https://www.chilkatsoft.com/")
success = json.UpdateInt("render.moduleSise",8)
success = fmt.QrCode("generate",json,jsonOut)
If (success = False) Then
    System.DebugLog("code: " + jsonOut.StringOf("errors[0].code"))
    System.DebugLog("path: " + jsonOut.StringOf("errors[0].path"))
    System.DebugLog("message: " + jsonOut.StringOf("errors[0].message"))
End If

//  2. A value out of range: QR versions are 1 to 40.
json.Clear 
success = json.UpdateString("payload.text","https://www.chilkatsoft.com/")
success = json.UpdateInt("encoding.qr.version",41)
success = fmt.QrCode("generate",json,jsonOut)
If (success = False) Then
    System.DebugLog("code: " + jsonOut.StringOf("errors[0].code"))
    System.DebugLog("path: " + jsonOut.StringOf("errors[0].path"))
    System.DebugLog("message: " + jsonOut.StringOf("errors[0].message"))
End If

//  3. Too much data: this text does not fit a version 1 symbol.
json.Clear 
success = json.UpdateString("payload.text","https://www.chilkatsoft.com/barcode_overview.asp")
success = json.UpdateInt("encoding.qr.version",1)
success = fmt.QrCode("generate",json,jsonOut)
If (success = False) Then
    System.DebugLog("code: " + jsonOut.StringOf("errors[0].code"))
    System.DebugLog("path: " + jsonOut.StringOf("errors[0].path"))
    System.DebugLog("message: " + jsonOut.StringOf("errors[0].message"))
End If

//  A program can act on the code.
If (jsonOut.StringOf("errors[0].code") = "capacityExceeded") Then
    System.DebugLog("The text is too long for the symbol size allowed.")
End If

//  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.