Integrating GraphQL with React Native; Apollo Client and Relay Client

In this guide, we will explore how to integrate GraphQL with React Native using two popular clients: Apollo Client and Relay Client. Both libraries offer powerful tools for working with GraphQL, but they have different approaches and features.

We will cover:

• Apollo Client Setup
  Integrate Apollo Client with React Native and connect to a GraphQL server.

• Relay Client Setup
  Configure Relay Client in your React Native project and set up a GraphQL environment.

APOLLO CLIENT SETUP

1. Install Apollo Client and Dependencies

   Install Apollo Client and related libraries using Yarn or npm:

   yarn add @apollo/client graphql
   

   or

   npm install @apollo/client graphql
   

2. Set Up Apollo Client

   Create an Apollo Client instance and configure it to connect to your GraphQL server. In your project directory, create a file named ApolloClient.js:

    // ApolloClient.js
    import { ApolloClient, InMemoryCache } from '@apollo/client';
   
    const client = new ApolloClient({
    uri: 'https://your-graphql-endpoint.com/graphql',
    cache: new InMemoryCache(),
    });
   
    export default client;
   

3. Integrate Apollo Client with React Native

   Wrap your application in an ApolloProvider to provide Apollo Client to your React Native components. Update your App.js file:

    // App.js
    import React from 'react';
    import { ApolloProvider } from '@apollo/client';
    import client from './ApolloClient';
    import YourMainComponent from './YourMainComponent';
   
    const App = () => (
    <ApolloProvider client={client}>
        <YourMainComponent />
    </ApolloProvider>
    );
   
    export default App;
   

4. Integrate Apollo Client with React Native

   Wrap your application in an ApolloProvider to provide Apollo Client to your React Native components. Update your App.js file:

    // YourComponent.js
    import React from 'react';
    import { Text, View } from 'react-native';
    import { useQuery, gql } from '@apollo/client';
   
    const GET_ITEMS = gql`
    query GetItems {
        items {
        id
        name
        }
    }
    `;
   
    const YourComponent = () => {
    const { loading, error, data } = useQuery(GET_ITEMS);
   
    if (loading) return <Text>Loading...</Text>;
    if (error) return <Text>Error: {error.message}</Text>;
   
    return (
        <View>
        {data.items.map(item => (
            <Text key={item.id}>{item.name}</Text>
        ))}
        </View>
    );
    };
   
    export default YourComponent;
   

RELAY CLIENT SETUP

1. Install Relay Client and Dependencies

   Install Relay and related packages:

    yarn add react-relay relay-runtime graphql
   

   or

    npm install react-relay relay-runtime graphql
   

2. Set Up Relay Environment

   Create a Relay Environment instance and configure it. In your project directory, create a file named RelayEnvironment.js:

    // RelayEnvironment.js
    import { Environment, Network, RecordSource, Store } from 'relay-runtime';
   
    const fetchQuery = async (operation, variables) => {
    const response = await fetch('https://your-graphql-endpoint.com/graphql', {
        method: 'POST',
        headers: {
        'Content-Type': 'application/json',
        },
        body: JSON.stringify({
        query: operation.text,
        variables,
        }),
    });
    return response.json();
    };
   
    const environment = new Environment({
    network: Network.create(fetchQuery),
    store: new Store(new RecordSource()),
    });
   
    export default environment;
   

3. Integrate Relay Environment with React Native

   Use the RelayEnvironmentProvider to provide Relay Environment to your components. Update your App.js file:

    // App.js
    import React from 'react';
    import { RelayEnvironmentProvider } from 'react-relay';
    import environment from './RelayEnvironment';
    import YourMainComponent from './YourMainComponent';
   
    const App = () => (
    <RelayEnvironmentProvider environment={environment}>
        <YourMainComponent />
    </RelayEnvironmentProvider>
    );
   
    export default App;
   

4. Querying Data with Relay Client

   Use the useLazyLoadQuery hook to fetch data in your components. For example:

    // YourComponent.js
    import React from 'react';
    import { Text, View } from 'react-native';
    import { graphql, useLazyLoadQuery } from 'react-relay/hooks';
   
    const GetItemsQuery = graphql`
    query YourComponentQuery {
        items {
        id
        name
        }
    }
    `;
   
    const YourComponent = () => {
    const data = useLazyLoadQuery(GetItemsQuery, {});
   
    return (
        <View>
        {data.items.map(item => (
            <Text key={item.id}>{item.name}</Text>
        ))}
        </View>
    );
    };
   
    export default YourComponent;
   

Summary

• Apollo Client is easy to set up and offers a flexible approach to managing GraphQL queries and caching.
• Relay Client provides a powerful, declarative approach to data fetching with built-in support for pagination and data normalization.

What other GraphQL topics would you like to see covered? Let me know in the comments!