Push notification in existing expo project - react-native

Question

I have an existing app in expo create in react-native. In that app I have to add expo push notification functionality. I have created the NotificationController using below link:
https://docs.expo.io/versions/v32.0.0/guides/push-notifications
I now need to know where I have to place this controller. I am very new in mobile development and just need help about the correct placement of this controller so that we can show this to the customer.

Answer 1

Once you have created your push notification service , either this can be a function in a single file in side your services directory (create if it doesn't exists) , or a component.
Then import that function inside your main app.js and use it inside componentDidMount lifecycle function. This is just a sample code and I'm sure this can be improved further, However this is enough to get started.
push_notification.js
import {Permissions, Notifications} from 'expo';
import { ActivityIndicator, AsyncStorage} from 'react-native';
export default async () => {
try{
let previousToken = await AsyncStorage.getItem('pushToken');
if(previousToken){
return;
}else{
let {status} = await Permissions.askAsync(Permissions.NOTIFICATIONS);
console.log(status);
if(status !== 'granted'){
console.log("Don't like to receive push");
}
let token = await Notifications.getExpoPushTokenAsync();
return token;
}
} catch(err){
console.log(err);
}
};
App.js
import PushNotification from "../services/push_notifications";
import axios from 'axios';
async componentDidMount(){
let tokenFromStorage = await zlAsyncStorage.getItem('pushToken');
console.log('token from storage',tokenFromStorage);return;
let token = await PushNotification();
AsyncStorage.setItem('pushToken',token);
console.log("here");
//Save the token in couch db
await axios({
url:"http://192.168.8.148:5984/mycompany",
method: 'post',
timeout: 1000,
headers: {
'Accept-Encoding' : 'gzip, deflate',
'Content-Type':'application/json',
'Authorization':'Basic YTph'
},
data: {
user: "cheran",
tokenReceived : token,
},
auth: {
username: 'a',
password: 'a'
},
}).then(function(response){
//console.log(response);
});
}