Generate random QR in react-native - reactjs

Question

I have generated QR Code manually by asking user to input value but what I'm trying is to generate QR Code random(Qr should be generated from number) without asking input from user so how can I generate random QR Code by pressing button only? I'm working on project that requires random QR Code every time when they open their mobile app.
Here is my code:
import React, { Component } from "react";
import {
StyleSheet,
View,
TextInput,
TouchableOpacity,
Text,
} from "react-native";
import QRCode from "react-native-qrcode-svg";
class QrGenerator extends Component {
constructor() {
super();
this.state = {
// Default Value of the TextInput
inputValue: "",
// Default value for the QR Code
valueForQRCode: "",
};
}
getTextInputValue = () => {
this.setState({
valueForQRCode: this.state.inputValue,
});
};
render() {
return (
<View style={styles.MainContainer}>
<QRCode
//Setting the value of QRCode
value={"ComputerGen" + this.state.valueForQRCode}
//Size of QRCode
size={250}
//Background Color of QRCode
bgColor="#000"
//Front Color of QRCode
fgColor="#fff"
getRef={(ref) => (this.svg = ref)}
onPress={() => {}}
/>
<TextInput // Input to get the value to set on QRCode
style={styles.TextInputStyle}
onChangeText={(text) => this.setState({ inputValue: text })}
underlineColorAndroid="transparent"
placeholder="Enter text to Generate QR Code"
/>
<TouchableOpacity
onPress={this.getTextInputValue}
activeOpacity={0.7}
style={styles.button}
>
<Text style={styles.TextStyle}> Generate QR Code </Text>
</TouchableOpacity>
</View>
);
}
}
export default QrGenerator;
const styles = StyleSheet.create({
MainContainer: {
flex: 1,
margin: 10,
alignItems: "center",
paddingTop: 40,
},
TextInputStyle: {
width: "100%",
height: 40,
marginTop: 20,
borderWidth: 1,
textAlign: "center",
},
button: {
width: "100%",
paddingTop: 8,
marginTop: 10,
paddingBottom: 8,
backgroundColor: "#F44336",
marginBottom: 20,
},
TextStyle: {
color: "#fff",
textAlign: "center",
fontSize: 18,
},
});

Answer 1

What you want to do is to make a random string "inputValue" if it is empty.
getTextInputValue = () => {
if (this.state.inputValue.length === 0) {
const randomInputValue = Math.random().toString(36).slice(2) + Math.random().toString(36).slice(2);
this.setState({
valueForQRCode: randomInputValue,
inputValue: randomInputValue,
});
} else {
this.setState({
valueForQRCode: this.state.inputValue,
});
}
};