qrcode

README

Go QR Code

QR Code encoder (Go).

Install

go get github.com/RashadAnsari/go-qrcode

Usage

import qrcode "github.com/RashadAnsari/go-qrcode"

Example

package main

import (
	"fmt"
	"image/color"
	"log"
	"os"

	qrcode "github.com/RashadAnsari/go-qrcode"
)

func main() {
	qr, err := qrcode.New("https://rashadansari.github.io", qrcode.High)
	if err != nil {
		log.Fatal(err.Error())
	}

	opacity := 100
	a := (float64(opacity) / float64(100)) * float64(255)
	qr.ForegroundColor = color.RGBA{R: 255, G: 0, B: 0, A: uint8(a)}

	writeToFile("qr.png", qr.PNG)
	writeToFile("qr.jpeg", qr.JPEG)
	writeToFile("qr.svg", qr.SVG)
	writeToFile("qr.pdf", qr.PDF)

	qr.Base64 = true

	stdoutBase64(qr.PNG)
	fmt.Println("----------")
	stdoutBase64(qr.JPEG)
	fmt.Println("----------")
	stdoutBase64(qr.PDF)
	fmt.Println("----------")
	stdoutBase64(qr.SVG)
}

func writeToFile(fileName string, FormatFunc func(_ int) ([]byte, error)) {
	size := 500
	fileMode := os.FileMode(0644)

	bytes, err := FormatFunc(size)
	if err != nil {
		log.Fatal(err.Error())
	}

	if err := os.WriteFile(fileName, bytes, fileMode); err != nil {
		log.Fatal(err.Error())
	}
}

func stdoutBase64(FormatFunc func(_ int) ([]byte, error)) {
	size := 500

	bytes, err := FormatFunc(size)
	if err != nil {
		log.Fatal(err.Error())
	}

	fmt.Println(string(bytes))
}

Maximum Capacity

The maximum capacity of a QR Code varies according to the content encoded and the error recovery level. The maximum capacity is 2,953 bytes, 4,296 alphanumeric characters, 7,089 numeric digits, or a combination.

Documentation

Index

• type QRCode
  • func New(content string, level RecoveryLevel) (*QRCode, error)
  • func (q *QRCode) JPEG(size int) ([]byte, error)
  • func (q *QRCode) PDF(size int) ([]byte, error)
  • func (q *QRCode) PNG(size int) ([]byte, error)
  • func (q *QRCode) SVG(size int) ([]byte, error)
• type RecoveryLevel

Types

type QRCode

type QRCode struct {

	// User settable drawing options.
	ForegroundColor color.Color
	BackgroundColor color.Color

	// Qr Code margin.
	Margin int

	// Base 64 output.
	Base64 bool
	// contains filtered or unexported fields
}

func New

func New(content string, level RecoveryLevel) (*QRCode, error)

func (*QRCode) JPEG

func (q *QRCode) JPEG(size int) ([]byte, error)

func (*QRCode) PDF

func (q *QRCode) PDF(size int) ([]byte, error)

func (*QRCode) PNG

func (q *QRCode) PNG(size int) ([]byte, error)

func (*QRCode) SVG

func (q *QRCode) SVG(size int) ([]byte, error)

type RecoveryLevel

type RecoveryLevel int

const (
	// Level L: 7% error recovery.
	Low RecoveryLevel = iota
	// Level M: 15% error recovery. Good default choice.
	Medium
	// Level Q: 25% error recovery.
	High
	// Level H: 30% error recovery.
	Highest
)