react-native-qrcode-svg

A QR Code generator for React Native based on react-native-svg and javascript-qrcode.

Discussion: https://discord.gg/RvFM97v

Features

* Easily render QR code images
* Optionally embed a logotype

| Android | iOS |
| - | - |
| | |

Installation

Install dependency packages

``bash
yarn add react-native-svg react-native-qrcode-svg
`
Or
`bash
npm i -S react-native-svg react-native-qrcode-svg
`

If you are using React Native 0.60.+ go to the folder your-project/ios and run pod install, and you're done.

If not, use one of the following method to link.

Link with react-native link

If you are using React Native <= 0.59.X, link the native project:

`bash
react-native link react-native-svg
`

Examples

`jsx
import QRCode from 'react-native-qrcode-svg';

// Simple usage, defaults for all but the value
render() {
return (
value="http://awesome.link.qr"
/>
);
};
`

`jsx
// 30px logo from base64 string with transparent background
render() {
let base64Logo = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAOEAA..';
return (
value="Just some string value"
logo={{uri: base64Logo}}
logoSize={30}
logoBackgroundColor='transparent'
/>
);
};
`

`jsx
// 20% (default) sized logo from local file string with white logo backdrop
render() {
let logoFromFile = require('../assets/logo.png');
return (
value="Just some string value"
logo={logoFromFile}
/>
);
};
`

`jsx
// get base64 string encode of the qrcode (currently logo is not included)
getDataURL() {
this.svg.toDataURL(this.callback);
}

callback(dataURL) {
console.log(dataURL);
}

render() {
return (
value="Just some string value"
getRef={(c) => (this.svg = c)}
/>
);
}
`

Props

Name | Default | Description
----------------|------------|--------------
size | 100 | Size of rendered image in pixels
value | 'this is a QR code' | String Value of the QR code. Can also accept an array of segments as defined in Manual mode. Ex. [{ data: 'ABCDEFG', mode: 'alphanumeric' }, { data: '0123456', mode: 'numeric' }, { data: [253,254,255], mode: 'byte' }]
color | 'black' | Color of the QR code
backgroundColor | 'white' | Color of the background
enableLinearGradient | false | enables or disables linear gradient
linearGradient | ['rgb(255,0,0)','rgb(0,255,255)'] | array of 2 rgb colors used to create the linear gradient
gradientDirection| [170,0,0,0] | the direction of the linear gradient
logo | null | Image source object. Ex. {uri: 'base64string'} or {require('pathToImage')}
logoSize | 20% of size | Size of the imprinted logo. Bigger logo = less error correction in QR code
logoBackgroundColor | backgroundColor | The logo gets a filled quadratic background with this color. Use 'transparent' if your logo already has its own backdrop.
logoMargin | 2 | logo's distance to its wrapper
logoBorderRadius | 0 | the border-radius of logo image (Android is not supported)
quietZone | 0 | quiet zone around the qr in pixels (useful when saving image to gallery)
getRef | null | Get SVG ref for further usage
ecl | 'M' | Error correction level
onError(error) | undefined | Callback fired when exception happened during the code generating process




Saving generated code to gallery

_Note: Experimental only ( not tested on iOS) , uses getRef() and needs RNFS module_

npm install --save react-native-fs

$3

`js
import { CameraRoll , ToastAndroid } from "react-native"
import RNFS from "react-native-fs"
...

saveQrToDisk() {
this.svg.toDataURL((data) => {
RNFS.writeFile(RNFS.CachesDirectoryPath+"/some-name.png", data, 'base64')
.then((success) => {
return CameraRoll.saveToCameraRoll(RNFS.CachesDirectoryPath+"/some-name.png", 'photo')
})
.then(() => {
this.setState({ busy: false, imageSaved: true })
ToastAndroid.show('Saved to gallery !!', ToastAndroid.SHORT)
})
})
}
`


Development and testing


This library comes with an Example App. You can find it in the directory ./Example.
Use the app to easily test your changes to react-native-qrcode-svg and when developing new features.

Read more details in the dedicated README.

Dependencies

$3

* react-native-svg

$3

* node-qrcode

$3

This library works seamlessly with React Native versions 0.75 and above. However, if you're using an older version of React Native (below 0.75), you might need to apply a custom transformation to your project's metro.config.js file to ensure compatibility with the TextEncoder API.

Here's how to configure the transformer for both Expo and React Native projects:

#### Setting Up the Transformer:
Make sure your project has a metro.config.js file. If not, create one at the root of your project.

#### Expo Projects:
`js
const { getDefaultConfig } = require("expo/metro-config");

module.exports = (() => {
const config = getDefaultConfig(__dirname);

const { transformer } = config;

config.transformer = {
...transformer,
babelTransformerPath: require.resolve("react-native-qrcode-svg/textEncodingTransformation")
};

return config;
})();
`
Merge the contents from your project's metro.config.js file with this config.

#### React Native Projects:
`js
const { getDefaultConfig, mergeConfig } = require("@react-native/metro-config");

const defaultConfig = getDefaultConfig(__dirname);

const config = {
transformer: {
babelTransformerPath: require.resolve("react-native-qrcode-svg/textEncodingTransformation"),
},
};

module.exports = mergeConfig(defaultConfig, config);
``