How to Use Google Directions API in React Native

Google's Directions API is a powerful tool that allows developers to incorporate directions and routing into their mobile applications. With this API, developers can easily draw routes on a map and also get information about the distance, time, and estimated cost of a journey.

In this tutorial, we will learn how to use the Google Directions API in a React Native application. We will cover the prerequisites, setting up the React Native project, installing dependencies, and using the Google Directions API in React Native. We will also discuss how to draw a route on a map in React Native and explore some use cases of Google's Directions API in mobile apps.

What is Google's Directions API?

Google's Directions API is a web service that provides directions and routing information for a given route. It is part of the Google Maps Platform and is used to calculate the fastest route between two points on a map. It can also be used to get information about the distance, time, and estimated cost of a journey.

The Google Directions API can be used in a variety of mobile apps, including those built with React Native. It is a powerful tool that can help developers create apps that provide users with detailed directions and routing information.

Prerequisites

Before we start, make sure you have the following:

• A Google Cloud Platform account
• A Google Maps Platform API Key
• A React Native development environment set up

Setting Up The React Native Project

First, create a new React Native project:

react-native init GoogleDirectionsApp

Then, install the react-native-maps package, which will allow us to draw the routes on a map:

npm install react-native-maps

Installing Dependencies & Setup

Next, install the react-native-geocoding package, which will allow us to convert addresses into geographic coordinates:

npm install react-native-geocoding

Then, install the axios package, which will allow us to make requests to the Google Directions API:

npm install axios

Finally, add the Google Maps Platform API key to the AndroidManifest.xml file:

<meta-data
    android:name="com.google.android.geo.API_KEY"
    android:value="YOUR_API_KEY"/>

How to Use Google Directions API in React Native?

To use the Google Directions API in React Native, we need to make a request to the API with the required parameters. The endpoint for the request is https://maps.googleapis.com/maps/api/directions/json.

The parameters required for the request are the origin and destination, which are the starting and ending points of the route. The origin and destination can be provided as an address, place ID, or geographic coordinates.

For example, if we want to get directions from New York City to San Francisco, we need to make the following request:

import axios from 'axios';

const API_KEY = 'YOUR_API_KEY';

const origin = 'New York City';
const destination = 'San Francisco';

axios.get(`https://maps.googleapis.com/maps/api/directions/json?origin=${origin}&destination=${destination}&key=${API_KEY}`)
  .then(res => {
    console.log(res.data);
  })
  .catch(err => {
    console.log(err);
  });

The response will be a JSON object containing the route information.

How to Draw a Route on a Map in React Native?

Once we have the route information, we can use the react-native-maps package to draw the route on a map.

First, import the MapView component from react-native-maps:

import MapView from 'react-native-maps';

Then, use the MapView.Polyline component to draw the route on the map:

<MapView
  style={styles.map}
  initialRegion={{
    latitude: 37.78825,
    longitude: -122.4324,
    latitudeDelta: 0.0922,
    longitudeDelta: 0.0421,
  }}
>
  <MapView.Polyline
    coordinates={routeCoordinates}
    strokeWidth={4}
    strokeColor="blue"
  />
</MapView>

The routeCoordinates array contains the geographic coordinates of the route.

Various Use Cases for Google's Directions API in Mobile Apps

Google's Directions API can be used in a variety of mobile apps. Here are some examples:

• Ride-hailing apps: Ride-hailing apps can use the Directions API to calculate estimated arrival times, estimated costs, and the fastest routes for drivers.

• Navigation apps: Navigation apps can use the Directions API to provide detailed turn-by-turn directions to users.

• Delivery apps: Delivery apps can use the Directions API to calculate the most efficient routes for delivery drivers.

Conclusion

In this tutorial, we learned how to use the Google Directions API in a React Native application. We covered the prerequisites, setting up the React Native project, installing dependencies, and using the Google Directions API in React Native. We also discussed how to draw a route on a map in React Native and explored some use cases of Google's Directions API in mobile apps.