GitHub - yeqown/go-qrcode: To help gophers generate QR Codes with customized styles, such as color, block size, block shape, and icon. (original) (raw)

go-qrcode

QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan. A barcode is a machine-readable optical label that contains information about the item to which it is attached. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used

Features

Normally generate QR code across version 1 to version 40.
Automatically analyze QR version by source text.
Specifying cell shape allowably with WithCustomShape, WithCircleShape (default is rectangle)
Specifying output file's format with WithBuiltinImageEncoder, WithCustomImageEncoder (default is JPEG)
Not only shape of cell, but also color of QR Code background and foreground color.
WithLogoImage, WithLogoImageFilePNG, WithLogoImageFileJPEG help you add an icon at the central of QR Code.
WithBorderWidth allows to specify any width of 4 sides around the qrcode.
WebAssembly support, check out the Example and README for more detail.
support Halftone QR Codes, check out the Example.

Install

go get -u github.com/yeqown/go-qrcode/v2

Quick Start

link to CODE

package main

import ( "github.com/yeqown/go-qrcode/v2" "github.com/yeqown/go-qrcode/writer/standard" )

func main() { qrc, err := qrcode.New("https://github.com/yeqown/go-qrcode") if err != nil { fmt.Printf("could not generate QRCode: %v", err) return }

w, err := standard.New("../assets/repo-qrcode.jpeg")
if err != nil {
    fmt.Printf("standard.New failed: %v", err)
    return
}

// save file
if err = qrc.Save(w); err != nil {
    fmt.Printf("could not save image: %v", err)
}

}

Options

const ( // EncModeNone mode ... EncModeNone encMode = 1 << iota // EncModeNumeric mode ... EncModeNumeric // EncModeAlphanumeric mode ... EncModeAlphanumeric // EncModeByte mode ... EncModeByte // EncModeJP mode ... EncModeJP )

// WithEncodingMode sets the encoding mode. func WithEncodingMode(mode encMode) EncodeOption {}

const ( // ErrorCorrectionLow :Level L: 7% error recovery. ErrorCorrectionLow ecLevel = iota + 1

// ErrorCorrectionMedium :Level M: 15% error recovery. Good default choice.
ErrorCorrectionMedium

// ErrorCorrectionQuart :Level Q: 25% error recovery.
ErrorCorrectionQuart

// ErrorCorrectionHighest :Level H: 30% error recovery.
ErrorCorrectionHighest

)

// WithErrorCorrectionLevel sets the error correction level. func WithErrorCorrectionLevel(ecLevel ecLevel) EncodeOption {}

Samples

These samples are generated with standard writer, check out Example for more details.

A	B	C	D
bg-fg color	transparent	border padding	circle shape
fg gradient	using halftone	set logo image	block width
custom shape

Built-in Writers

Standard Writer, prints QRCode into file and stream
Terminal Writer, prints QRCode into terminal
File Writer, prints QRCode into files
Compressed Writer, It's generated on a very small scale

Of course, you can also code your own writer, just implement Writer interface.

Migrating from v1

go-qrcode.v2 is a major upgrade from v1, and it is not backward compatible. v2 redesigned the API, and it is more flexible and powerful. Features are split into different modules (according to functionality).

github.com/yeqown/go-qrcode/v2 core
github.com/yeqown/go-qrcode/writer/standard writer/imageFile
github.com/yeqown/go-qrcode/writer/terminal writer/terminal

Check example/migrating-from-v1 for more details.