Unicode C++ Requires Chilkat v11.7.0+
Unicode 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 Unicode C++ Downloads
#include <CkFormatsW.h>
#include <CkJsonObjectW.h>
void ChilkatSample(void)
{
bool success = false;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
CkFormatsW fmt;
CkJsonObjectW json;
CkJsonObjectW jsonOut;
// 1. A misspelled option: "moduleSise" for "moduleSize".
json.UpdateString(L"payload.text",L"https://www.chilkatsoft.com/");
json.UpdateInt(L"render.moduleSise",8);
success = fmt.QrCode(L"generate",json,jsonOut);
if (success == false) {
wprintf(L"code: %s\n",jsonOut.stringOf(L"errors[0].code"));
wprintf(L"path: %s\n",jsonOut.stringOf(L"errors[0].path"));
wprintf(L"message: %s\n",jsonOut.stringOf(L"errors[0].message"));
}
// 2. A value out of range: QR versions are 1 to 40.
json.Clear();
json.UpdateString(L"payload.text",L"https://www.chilkatsoft.com/");
json.UpdateInt(L"encoding.qr.version",41);
success = fmt.QrCode(L"generate",json,jsonOut);
if (success == false) {
wprintf(L"code: %s\n",jsonOut.stringOf(L"errors[0].code"));
wprintf(L"path: %s\n",jsonOut.stringOf(L"errors[0].path"));
wprintf(L"message: %s\n",jsonOut.stringOf(L"errors[0].message"));
}
// 3. Too much data: this text does not fit a version 1 symbol.
json.Clear();
json.UpdateString(L"payload.text",L"https://www.chilkatsoft.com/barcode_overview.asp");
json.UpdateInt(L"encoding.qr.version",1);
success = fmt.QrCode(L"generate",json,jsonOut);
if (success == false) {
wprintf(L"code: %s\n",jsonOut.stringOf(L"errors[0].code"));
wprintf(L"path: %s\n",jsonOut.stringOf(L"errors[0].path"));
wprintf(L"message: %s\n",jsonOut.stringOf(L"errors[0].message"));
}
// A program can act on the code.
if (jsonOut.stringOf(L"errors[0].code") == L"capacityExceeded") {
wprintf(L"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.
}