C Requires Chilkat v11.7.0+
C
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.Chilkat C Downloads
#include <C_CkFormats.h>
#include <C_CkJsonObject.h>
void ChilkatSample(void)
{
BOOL success;
HCkFormats fmt;
HCkJsonObject json;
HCkJsonObject jsonOut;
success = FALSE;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
fmt = CkFormats_Create();
json = CkJsonObject_Create();
jsonOut = CkJsonObject_Create();
// 1. A misspelled option: "moduleSise" for "moduleSize".
CkJsonObject_UpdateString(json,"payload.text","https://www.chilkatsoft.com/");
CkJsonObject_UpdateInt(json,"render.moduleSise",8);
success = CkFormats_QrCode(fmt,"generate",json,jsonOut);
if (success == FALSE) {
printf("code: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].code"));
printf("path: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].path"));
printf("message: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].message"));
}
// 2. A value out of range: QR versions are 1 to 40.
CkJsonObject_Clear(json);
CkJsonObject_UpdateString(json,"payload.text","https://www.chilkatsoft.com/");
CkJsonObject_UpdateInt(json,"encoding.qr.version",41);
success = CkFormats_QrCode(fmt,"generate",json,jsonOut);
if (success == FALSE) {
printf("code: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].code"));
printf("path: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].path"));
printf("message: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].message"));
}
// 3. Too much data: this text does not fit a version 1 symbol.
CkJsonObject_Clear(json);
CkJsonObject_UpdateString(json,"payload.text","https://www.chilkatsoft.com/barcode_overview.asp");
CkJsonObject_UpdateInt(json,"encoding.qr.version",1);
success = CkFormats_QrCode(fmt,"generate",json,jsonOut);
if (success == FALSE) {
printf("code: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].code"));
printf("path: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].path"));
printf("message: %s\n",CkJsonObject_stringOf(jsonOut,"errors[0].message"));
}
// A program can act on the code.
if (CkJsonObject_stringOf(jsonOut,"errors[0].code") == "capacityExceeded") {
printf("The text is too long for the symbol size allowed.\n");
}
// 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.
CkFormats_Dispose(fmt);
CkJsonObject_Dispose(json);
CkJsonObject_Dispose(jsonOut);
}