qrcode

Overview ¶

Package qrcode generates QR code images from string content.

It produces PNG-encoded QR codes as raw bytes or base64 data URIs, using medium error correction (recovers up to 15% damage). The default image size is 256x256 pixels.

Basic Usage ¶

Generate a QR code as PNG bytes:

import "github.com/dmitrymomot/forge/pkg/qrcode"

png, err := qrcode.Generate("https://example.com")
if err != nil {
	log.Fatal(err)
}
// png contains the raw PNG image bytes

Generate a data URI for embedding in HTML:

dataURI, err := qrcode.GenerateBase64Image("https://example.com")
if err != nil {
	log.Fatal(err)
}
// use in HTML: <img src="{{dataURI}}">

Custom Size ¶

Pass an optional size in pixels:

png, err := qrcode.Generate("https://example.com", 512)

TOTP Integration ¶

Pair with the totp package to generate authenticator app QR codes:

import (
	"github.com/dmitrymomot/forge/pkg/qrcode"
	"github.com/dmitrymomot/forge/pkg/totp"
)

secret, err := totp.GenerateSecretKey()
if err != nil {
	log.Fatal(err)
}

uri, err := totp.GetTOTPURI(totp.TOTPParams{
	Secret:      secret,
	AccountName: "user@example.com",
	Issuer:      "MyApp",
})
if err != nil {
	log.Fatal(err)
}

dataURI, err := qrcode.GenerateBase64Image(uri)
if err != nil {
	log.Fatal(err)
}
// Render dataURI in an <img> tag for the user to scan

Error Handling ¶

The package returns ErrEmptyContent for empty or whitespace-only input and ErrFailedToGenerateQRCode for encoding failures:

png, err := qrcode.Generate("")
if errors.Is(err, qrcode.ErrEmptyContent) {
	// handle empty content
}