App.js

import Constants from "expo-constants";
import * as Notifications from "expo-notifications";
import React, { useState, useEffect, useRef } from "react";
import { Text, View, Button, Platform } from "react-native";

Notifications.setNotificationHandler({
  handleNotification: async () => ({
    shouldShowAlert: true,
    shouldPlaySound: false,
    shouldSetBadge: false,
  }),
});

export default function App() {
  const [expoPushToken, setExpoPushToken] = useState("");
  const [notification, setNotification] = useState(false);
  const notificationListener = useRef();
  const responseListener = useRef();

  useEffect(() => {
    registerForPushNotificationsAsync().then((token) =>
      setExpoPushToken(token)
    );

    // This listener is fired whenever a notification is received while the app is foregrounded
    notificationListener.current = Notifications.addNotificationReceivedListener(
      (notification) => {
        setNotification(notification);
      }
    );

    // This listener is fired whenever a user taps on or interacts with a notification (works when app is foregrounded, backgrounded, or killed)
    responseListener.current = Notifications.addNotificationResponseReceivedListener(
      (response) => {
        console.log(response);
      }
    );

    return () => {
      Notifications.removeNotificationSubscription(notificationListener);
      Notifications.removeNotificationSubscription(responseListener);
    };
  }, []);

  return (
    <View
      style={{
        flex: 1,
        alignItems: "center",
        justifyContent: "space-around",
      }}
    >
      <Text>Your expo push token: {expoPushToken}</Text>
      <View style={{ alignItems: "center", justifyContent: "center" }}>
        <Text>
          Title: {notification && notification.request.content.title}{" "}
        </Text>
        <Text>Body: {notification && notification.request.content.body}</Text>
        {/* <Text>
          Data:{" "}
          {notification && JSON.stringify(notification.request.content.data)}
        </Text> */}
      </View>
      <Button
        title="Press to Send Notification"
        onPress={async () => {
          await sendPushNotification(expoPushToken);
        }}
      />
    </View>
  );
}

// Can use this function below, OR use Expo's Push Notification Tool-> https://expo.io/notifications
async function sendPushNotification(expoPushToken) {
  const message = {
    to: expoPushToken,
    sound: "default",
    title: "Expo push Notification",
    body: "Hi there!",
    //   data: { Data: "You just received a notification from Expo" },
  };

  await fetch("https://exp.host/--/api/v2/push/send", {
    method: "POST",
    headers: {
      Accept: "application/json",
      "Accept-encoding": "gzip, deflate",
      "Content-Type": "application/json",
    },
    body: JSON.stringify(message),
  });
}

async function registerForPushNotificationsAsync() {
  let token;
  if (Constants.isDevice) {
    const {
      status: existingStatus,
    } = await Notifications.getPermissionsAsync();
    let finalStatus = existingStatus;
    if (existingStatus !== "granted") {
      const { status } = await Notifications.requestPermissionsAsync();
      finalStatus = status;
    }
    if (finalStatus !== "granted") {
      alert("Failed to get push token for push notification!");
      return;
    }
    token = (await Notifications.getExpoPushTokenAsync()).data;
    console.log(token);
  } else {
    alert("Must use physical device for Push Notifications");
  }

  if (Platform.OS === "android") {
    Notifications.setNotificationChannelAsync("default", {
      name: "default",
      importance: Notifications.AndroidImportance.MAX,
      vibrationPattern: [0, 250, 250, 250],
      lightColor: "#FF231F7C",
    });
  }

  return token;
}