QR Scanner

Access: startiapp.QrScanner

For a step-by-step guide to scanning QR codes — including validation and continuous scanning — see Scan QR Codes.

Methods

`scan(options?): Promise<string | null>`

Opens the QR code scanner. Returns the scanned value when a code is read, or null if the scanner is already running.

When a validation function is provided, the scanner stays open and keeps scanning until the validation function returns true. This is useful for rejecting invalid codes without closing the scanner.

Parameters:

Parameter	Type	Required	Description
options	`QrScannerOptions`	No	Scanner configuration and optional validation

Returns: Promise<string | null> —The scanned QR code string, or null if a scan is already in progress.

Example:

// Basic scan
const result = await startiapp.QrScanner.scan();

if (result) {
  console.log("Scanned:", result);
}

// Choose front camera, hide switch button
const result = await startiapp.QrScanner.scan({
  cameraFacing: "front",
  showCameraSwitchButton: false,
});

// With async validation (scanner stays open until valid code is scanned)
const validResult = await startiapp.QrScanner.scan({
  validation: async (scannedValue) => {
    // e.g. check against your server
    const response = await fetch(`/api/validate?code=${scannedValue}`);
    return response.ok;
  },
});

console.log("Valid code scanned:", validResult);

// With synchronous validation
const result = await startiapp.QrScanner.scan({
  validation: (scannedValue) => {
    return scannedValue.startsWith("VALID_");
  },
});

`stop(): Promise<void>`

Stops the QR code scanner and closes the camera view.

Returns: Promise<void>

Example:

await startiapp.QrScanner.stop();

`isCameraAccessGranted(): Promise<boolean>`

Checks whether camera access has been granted.

Returns: Promise<boolean> —true if camera access is granted.

Example:

const granted = await startiapp.QrScanner.isCameraAccessGranted();

if (!granted) {
  await startiapp.QrScanner.requestCameraAccess();
}

`requestCameraAccess(): Promise<void>`

Requests camera permission from the user. Shows the platform's native permission dialog.

Returns: Promise<void>

Example:

await startiapp.QrScanner.requestCameraAccess();

Events

`qrCodeScanned`

Fired each time a QR code is successfully scanned. This event fires even when using the validation option, allowing you to react to every scan attempt.

Event data: string —The scanned QR code value.

Example:

startiapp.QrScanner.addEventListener("qrCodeScanned", (event) => {
  console.log("Code scanned:", event.detail);
});

`qrScannerClosed`

Fired when the QR scanner is closed (either by the user or programmatically).

Event data: None.

Example:

startiapp.QrScanner.addEventListener("qrScannerClosed", () => {
  console.log("Scanner was closed");
});

Types

`QrScannerOptions`

type QrScannerOptions = {
  /** Whether to show the camera preview while scanning. Default: true. */
  showCameraPreview?: boolean;
  /** Which camera to use. Default: "back". */
  cameraFacing?: "front" | "back";
  /** Whether to show the camera switch button. Default: true. */
  showCameraSwitchButton?: boolean;
  /** Optional validation function. Scanner stays open until it returns true. */
  validation?: (scannedValue: string) => boolean | Promise<boolean>;
};

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