The following code snippet serves a QRCode using Deno.
URL Params Example:
http://localhost:4000/?d=Hello+World!&v=5&e=L&s=250&m=Byte
import { qrcode } from "https://deno.land/x/qrcode/mod.ts";
import { decodeBase64 } from "https://deno.land/std@0.204.0/encoding/base64.ts";
// Deno.serve() handler
async function handler(request: Request, connInfo: Deno.ServeHandlerInfo): Promise<Response> {
// Information for a HTTP request.
const remoteAddr = connInfo.remoteAddr;
const url = new URL(request.url);
// Data to encode...
const d = url.searchParams.get("d") || "Hello World!";
// Version of barcode 0 (Automatic type number) - 40
// https://www.qrcode.com/en/about/version.html
const v = Math.min(40, Math.max(0, Number(url.searchParams.get("v")) || 0));
// Error Correction L = 7% | M = 15% | Q = 25% | H = 30%
const e = ["L", "M", "Q", "H"].includes(url.searchParams.get("e")) ? url.searchParams.get("e") : "M";
// Size of barcode 250 - 500
const s = Math.min(500, Math.max(250, Number(url.searchParams.get("s")) || 250));
// Mode = 'Numeric' | 'Alphanumeric' | 'Byte' | 'Kanji'
const m = ['Numeric', 'Alphanumeric', 'Byte', 'Kanji'].includes(url.searchParams.get("m")) ? url.searchParams.get("m") : "Byte";
const base64Image = await qrcode(d, { typeNumber: v, errorCorrectLevel: e, size: s, mode: m }); // data:image/gif;base64,...
const binaryImage = new Uint8Array(decodeBase64(base64Image.split(",")[1]));
return new Response(binaryImage, {
status: 200,
headers: {
"Server": `Deno v${Deno.version.deno}`,
"Allow": "HEAD, GET, OPTIONS",
"Cache-Control": "no-store",
"Content-Language": "en-US",
"Access-Control-Allow-Origin": "*",
"Access-Control-Allow-Methods": "HEAD, GET, OPTIONS",
"Access-Control-Allow-Headers": "Content-Type",
"Access-Control-Allow-Credentials": "false",
"Content-Type": "image/gif",
},
})
}
// Start the QRCode server of Port 4000
Deno.serve({
port: 4000,
hostname: "0.0.0.0",
onListen({ port, hostname }) {
console.log(`Application..... QR Code - Model 2 - A QR Code Model 2 Server
Deno v${Deno.version.deno} : Typescript v${Deno.version.typescript} : V8 v${Deno.version.v8}
Permissions..... --allow-net
Gateway URL..... http://${hostname}:${port}\n\n`);
},
onError(error: unknown) {
console.error(error);
return new Response("HTTP 500: Internal Server Error", {
status: 500,
headers: { "Content-Type": "text/plain" },
});
},
}, handler);
// deno run --allow-net qrServe.tsHello World!
The following code snippet serves a QRCode using Deno.
URL Params Example:
http://localhost:4000/?d=Hello+World!&v=5&e=L&s=250&m=ByteHello World!