GoQRIS

GoQRIS is a lightweight, modular Golang library designed to process and manipulate QRIS (Quick Response Code Indonesian Standard) codes. This library focuses on converting a Static QRIS into a Dynamic QRIS by dynamically injecting a transaction amount (Tag 54) and accurately recalculating the mandatory Checksum (CRC16-CCITT).

This library is built with a strictly Zero-Dependency approach in its go.mod.

Features

• Convert Static to Dynamic: Automatically updates the initiation method indicator (Tag 01) from 11 (Static) to 12 (Dynamic).
• Nominal Injection: Seamlessly injects the transaction amount (Tag 54) into the TLV (Tag-Length-Value) structure.
• Auto CRC16 Recalculation: Automatically drops the old checksum and recalculates a highly accurate CRC16-CCITT checksum for the new string.
• Multi-Input Support: Extract and process QRIS from multiple sources:
  • Raw String
  • Local File Path (.png, .jpg)
  • Internet Image URL
  • io.Reader (Perfect for HTTP API multipart/form-data uploads).

Scanner Engine Origin

The internal QR Code reader engine used in this library is an extracted, vendored version of makiuchi-d/gozxing, which is a Golang port of the renowned ZXing (Zebra Crossing) library.

To maintain the strict zero-dependency rule in our go.mod file, the necessary computer vision and Reed-Solomon error correction components from gozxing were manually copied and embedded directly into the gozxing/ directory of this repository. This vendor-in-tree approach guarantees that this library remains robust and immune to any future upstream changes, repository deletions, or broken dependencies, giving you full control over the core logic.

Installation

To install the library, simply run the following go get command:

go get github.com/xiaojam/goqris

Usage and Sample Implementation

Below is a complete, ready-to-run example demonstrating how to use the library across different scenarios (String, URL, and Local File).

You can create a main.go file in your project and run this code:

package main

import (
	"fmt"
	"log"
	"os"

	"github.com/xiaojam/goqris/service" 
)

func main() {
	// ---------------------------------------------------------
	// FROM STRING
	// ---------------------------------------------------------

	nominal := "125000"

	rawString := "0002010102115204411153033605802ID5904Toko6007Jakarta6304A1B2"
	
	resStr, err := service.ProcessFromString(rawString, nominal)
	if err != nil {
		log.Println(err)
	} else {
		fmt.Printf("Nominal     : Rp %s\n", nominal)
		fmt.Printf("Old String  : %s\n", resStr.OriginalString)
		fmt.Printf("New String  : %s\n", resStr.NewString)
		fmt.Printf("New CRC     : %s\n", resStr.CRCValue)
	}

	// ---------------------------------------------------------
	// FROM URL
	// ---------------------------------------------------------
	urlGambar := "https://raw.githubusercontent.com/xiaojam/goqris/main/example/qris.jpg"
	
	resUrl, err := service.ProcessFromURL(urlGambar, nominal)
	if err != nil {
		log.Println(err)
	} else {
		fmt.Println("New String  :", resUrl.NewString)
	}
	
	// ---------------------------------------------------------
	// FROM LOCAL PATH
	// ---------------------------------------------------------
	dummyPath := "./qris.jpg"
	_ = os.WriteFile(dummyPath, []byte("this is not image"), 0644)
	defer os.Remove(dummyPath) 

	resPath, err := service.ProcessFromPath(dummyPath, nominal)
	if err != nil {
		log.Println(err)
	} else {
		fmt.Println("New String  :", resPath.NewString)
	}
}

Implementing in HTTP APIs (Using io.Reader)

If you are building a REST API where users upload QRIS images, you can directly pass the multipart.File into the library using ProcessFromImage:

// Inside your HTTP Handler
file, _, err := r.FormFile("qris_image")
if err != nil {
    http.Error(w, "Failed to get file", http.StatusBadRequest)
    return
}
defer file.Close()

// file is of type multipart.File, which implements io.Reader
response, err := service.ProcessFromImage(file, "200000")
if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
}

fmt.Fprintln(w, "Dynamic QRIS: ", response.NewString)

Project Structure

• model/ : Contains the TLV item structures and Process Response schemas.
• util/ : Houses the TLV string parser engine and the CRC16-CCITT cryptographic recalculation logic.
• service/ : The Core Business Logic handling the transformation of Static QRIS to Dynamic.
• gozxing/ : An internally vendored, zero-dependency QR code decoding engine ported from makiuchi-d/gozxing.

License

This project is licensed under the MIT License.