QRCode

$qrcode.encode(text)

Encodes a non-empty string as a QR code image and returns a PNG base64 string.

const image = $qrcode.encode("https://example.com")

text must be a non-empty string. Non-string values throw text must be a string; empty strings throw QR code content must not be empty.

$qrcode.decode(image)

Decodes a QR code from a base64 image string and returns the decoded text.

image can be a plain base64 string or a data URL such as data:image/png;base64,.... Common Android bitmap formats are supported, including PNG, JPEG, and WebP.

const image = $qrcode.encode("hello")
const text = $qrcode.decode(image)

console.log(text) // "hello"

Invalid base64, unsupported image data, or an image without a QR code throws an error.

$qrcode.scan(callback)

Opens the native camera scanner. When a QR code is found, callback is called with the decoded text.

$qrcode.scan((text) => {
  console.log(text)
})

scan is callback based and does not return a Promise.

$qrcode.scan(options)

Opens the native camera scanner with options.

$qrcode.scan({
  useFrontCamera: false,
  turnOnFlash: false,
  handler(text) {
    console.log(text)
  },
  cancelled() {
    console.log("Scan cancelled")
  }
})

useFrontCamera selects the front camera when supported. turnOnFlash requests torch mode for the back camera. handler is called when a QR code is scanned. cancelled is called when the scanner is cancelled, camera permission is denied, or the scanner fails to start.