Simple local notification with Expo

LocalNotifications.js

import React, {Component} from 'react';
import {TextInput, View, Keyboard} from 'react-native';
import {Constants, Notifications, Permissions} from 'expo';

export default class Timer extends Component {
    onSubmit(e) {
        Keyboard.dismiss();

        const localNotification = {
            title: 'done',
            body: 'done!'
        };

        const schedulingOptions = {
            time: (new Date()).getTime() + Number(e.nativeEvent.text)
        }

        // Notifications show only when app is not active.
        // (ie. another app being used or device's screen is locked)
        Notifications.scheduleLocalNotificationAsync(
            localNotification, schedulingOptions
        );
    }

    handleNotification() {
        console.warn('ok! got your notif');
    }

    async componentDidMount() {
        // We need to ask for Notification permissions for ios devices
        let result = await Permissions.askAsync(Permissions.NOTIFICATIONS);

        if (Constants.isDevice && result.status === 'granted') {
            console.log('Notification permissions granted.')
        }

        // If we want to do something with the notification when the app
        // is active, we need to listen to notification events and 
        // handle them in a callback
        Notifications.addListener(this.handleNotification);
    }

    render() {
        return (
            <View style={{flex: 1, flexDirection: 'row', justifyContent: 'center'}}>
                <TextInput
                    onSubmitEditing={this.onSubmit}
                    placeholder={'time in ms'}
                />
            </View>
        );
    }
};