Welcome folks today in this blog post we will be generating qr codes in node.js and javascript using qrcode library. All the full source code of application is given below.
Get Started
In order to get started you need to install the qrcode library globally inside your node.js application by executing the below command
npm i -g qrcode
After executing this command you can generate simple qr codes using the below command
qrcode "some text"
You can see that it generates instantly the qr code in the console.
Now you can also provide additional parameter of color of qr code in the below command to generate colored qr codes
qrcode -d F00 -o out.png "sample text"
Now in the command you will see two additional parameters been added
-d stands for dark color of qr code as foreground here we are providing the qr code of red
-o stands for output file and we have name of out.png file
If you execute this command you will see the following result
Browser Usage
You can use this node-qrcode library in the browser side as shown below
<!-- index.html -->
<html>
<body>
<canvas id="canvas"></canvas>
<script src="bundle.js"></script>
</body>
</html>
// index.js -> bundle.js
var QRCode = require('qrcode')
var canvas = document.getElementById('canvas')
QRCode.toCanvas(canvas, 'sample text', function (error) {
if (error) console.error(error)
console.log('success!');
})
<canvas id="canvas"></canvas>
<script src="/build/qrcode.min.js"></script>
<script>
QRCode.toCanvas(document.getElementById('canvas'), 'sample text', function (error) {
if (error) console.error(error)
console.log('success!');
})
</script>
Node.js Usage
You can also use this library as a standalone application inside node.js as shown below
npm i qrcode
After installing this inside node.js project you need to make an index.js file and copy paste the following code
index.js
var QRCode = require('qrcode')
QRCode.toDataURL('I am a pony!', function (err, url) {
console.log(url)
})
Now if you execute this node.js project it will convert the text to base64 string url as shown below
Now if you want to generate the qr code inside node.js with the help of this library you can copy paste the following code which is given below
var QRCode = require('qrcode')
QRCode.toString('I am a pony!',{type:'terminal'}, function (err, url) {
console.log(url)
})
