Consuming GraphQL API With React.js

If you have created your GraphQL APIs and are looking to consume them in a React front-end, learn how to consume your GraphQL API using React.js in this post.

Rose Chege

Jun. 19, 24 · Tutorial

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GraphQL is a query language that allows clients to request exactly the data they need and nothing more. This approach is more efficient than REST. This is because its structure allows for flexible data-fetching techniques. If you have created your GraphQL APIs and are looking to consume them in a React front-end, you have come to the right place. This article will teach you how to consume your GraphQL API using React.js.

Prerequisites

To continue in this article, it is helpful to have the following:

Node.js installed on your computer
Prior experience working with JavaScript and GraphQL
You will require a working GraphQL API. For demonstration purposes, this guide will use Fruit GraphQL API to interact with its data using React.js.

Setting Up the Application

To create a React.js application, launch your terminal from your preferred working directory and run the npx create-react-app command as follows:

npx create-react-app fruits_app

This command will use the create-react-app package to set up a new React application. The command will install all the necessary dependencies and configuration files to get a basic React application up and running.

Once the setup process is completed, navigate to the newly created fruits_app directory to proceed with the next steps:

cd fruits_app

Along this guide, you will be required to install the following dependencies:

Apollo Client: For provisioning GraphQL client functionalities
GraphQL: For writing GraphQL mutation and query
React-router-dom: For redirecting to pages

To install them, execute the following command in your fruits_app directory:

npm i @apollo/client graphql react-router-dom

Setting Up the Components

Before diving in and interacting with data, let's first build the application skeleton to streamline the app. In the project's directory, create a components directory. The components directory will host two files, namely:

Layout.js : For defining the application layout
Navbar.js : For the application's navbar

Go ahead and create the above files in the designated directory.

Below is how the application's navbar will look like in the Navbar.js:

    JavaScript
   
 

   import React from 'react'

export default function Navbar() {
return (
    <nav className='navbar'>
        <div>
            <div className='navbar-brand'>
                Fruits App
            </div>
            <div className='nav-links'>
                <ul>
                    <li>
                        <a href="/">Fruits</a>
                    </li>
                    <li>
                        <a href="/add-fruit">Add Fruit</a>
                    </li>
                </ul>
            </div>
        </div>
    </nav>
)
}
  

Layout.js will build the application layout as follows:

    JavaScript
   
 

   import React from 'react';
import Navbar from './Navbar';

export default function Layout({children}) {
    return (
        <div>
            <Navbar/>
            {children}
        </div>
    )
}
  

Modify App.css to add the styles for the navbar:

    JavaScript
   
 

   .navbar{    width: 100%;    padding: 20px;    border-bottom: 1px solid #d4d4d4;
}

.navbar div{    display: flex;    justify-content: center;
}

.navbar .navbar-brand{    width: 30%;    font-weight: bold;
}

.navbar .nav-links{    width: 70%;
}

.navbar .nav-links ul{    display: flex;    padding: 0px;    margin:0px;    list-style-type: none;
}

.navbar .nav-links ul li{    margin-right: 10px;
}

.navbar .nav-links ul li a{    text-decoration: none;
}
  

Similarly, in the project directory, create a pages directory. In the directory, create two files, i.e.:

Fruits.js: This will serve as the application home page to interact with GraphQL queries.
AddFruit.js: This will create a simple form for adding a fruit page to interact with GraphQL mutation.

For the application to access the above files, navigate to the src/App.js and add the following changes:

Import the necessary packages:

    JavaScript
   
   import {BrowserRouter,Routes,Route} from 'react-router-dom';
import Layout from './components/Layout';
import Fruits from './pages/Fruits';
import AddFruit from './pages/AddFruit';

Inside the render function: Define a component that will be rendered in case of a route that does not exist:

const NoPage = () => <p>No such page exists</p>

Finally, return the routes definition:

    JavaScript
   
 

   <BrowserRouter>
    <Routes>
        <Route path="/" element={<Layout />}/>
        <Route index element={<Fruits />} />
        <Route path="/add-fruit" element={<AddFruit />} />
        <Route path="*" element={NoPage} />
    </Routes>
</BrowserRouter>
  

Configuring Apollo Client

Let's now dive in and handle the GraphQL functionality on the React front end. To consume GraphQL with React, you will need to use the Apollo Client that we installed earlier.

Apollo Server is a flexible GraphQL client for any front-end frameworks such as React, Angular, Vue.js, and React Native. Apollo Client provides features such as caching, real-time subscriptions, and automatic data management that make it easy to work with GraphQL data in your application.

To configure Apollo Client, navigate to the index.js and import the @apollo/client features as follows:

import {ApolloClient,InMemoryCache,ApolloProvider} from '@apollo/client';

In the same file, define the Apollo Client:

    JavaScript
   
   const client = new ApolloClient({
    uri:'https://fruits-api.netlify.app/graphql',
    cache: new InMemoryCache()
})

Encapsulate the rendered components with the Apollo Provider component as follows:

    JavaScript
   
 

   root.render(
<ApolloProvider client={client}>
    <React.StrictMode>
    <App />
    </React.StrictMode>
</ApolloProvider>
);
  

Getting All Fruits

Let's now start interacting with the GrapgQL data. To fetch the fruit data from the API, navigate to the pages/Fruits.js files and implement the following changes:

Import the necessary packages:

    JavaScript
   
   import {useQuery,gql} from '@apollo/client';
import Layout from '../components/Layout';
import '../App.css';

Define a GraphQL query for getting the fruits:

    JavaScript
   
 

   const GET_FRUITS = gql`
    query fruits{
    fruits{
        id
        tree_name
        scientific_name
        family
        origin
    }
    }
`;
  

Define a render function:

    JavaScript
   
   function App() {
}

Inside the above render function, make the following the following changes:

Send the query for fetching the data as follows:

    JavaScript
   
   const {loading,error,data} = useQuery(GET_FRUITS);

Check whether it is loading or there is an error when getting the data:

    JavaScript
   
   if(loading) return <p>Loading...</p>;
if(error) return <p>Error: {error.message}</p>

Render the fruits and display them on React as follows:

    JSX
   
 

   return (
    <Layout>
    <div className="App">
        {
        data.fruits.map(({id,tree_name,scientific_name,family,origin}) => (
            <div key={id} className="fruitCard">
            <h3>Name: {tree_name}</h3>
            <h4>Scientific name: {scientific_name}</h4>
            <h5>Family: {family}</h5>
            <h5>Origin: {origin}</h5>
            </div>
        ))
        }
    </div>
    </Layout>
);
  

Modify App.css to have a style for fruitCard:

    JavaScript
   
 

   .fruitCard{
    text-align: left;
    border: 1px solid #d4d4d4;
    margin-left: 10px;
    margin-bottom: 10px;
    margin-top:10px;
    padding:10px;
}
  

Now ensure the development server is running by executing the following command:

    JavaScript
   
   npm run start

Opening http://localhost:3000/ on the browser, React should be able to display the data as follows:

Adding a Fruit

Adding data using a GrapgQl API involves sending a mutation. Mutations Resolvers allow changing your data. This includes adding, deleting, or updating the API data. To add data, navigate to pages/AddFruit.js and make the following changes:

Import the necessary packages:

    JavaScript
   
   import React,{useState} from 'react';
import {gql,useMutation} from '@apollo/client';
import Layout from '../components/Layout';
import '../App.css';

Define a render function:

    JavaScript
   
   export default function AddFruit() {
}

Define the states for the form elements:

    JavaScript
   
 

   const [id,setId] = useState();
const [scientific_name,setScientificName] = useState();
const [tree_name,setTreeName] = useState();
const [fruit_name,setFruitName] = useState();
const [family,setFamily] = useState();
const [origin,setOrigin] = useState();
const [description,setDescription] = useState();
const [bloom,setBloom] = useState();
const [maturation_fruit,setMaturationFruit] = useState();
const [life_cycle,setLifeCycle] = useState();
const [climatic_zone,setClimaticZone] = useState();
const [formError,setFormError] = useState();
const [message,setMessage] = useState("");
  

Define the GraphQL mutation query:

    JavaScript
   
 

   const newFruit = gql`
    mutation addFruit($id:ID!,
        $scientific_name:String!,
        $tree_name:String!,
        $fruit_name:String!,
        $family:String!,
        $origin:String!,
        $description:String!,
        $bloom:String!,
        $maturation_fruit:String!,
        $life_cycle:String!,
        $climatic_zone:String!){
        addFruit(id:$id,
        scientific_name:$scientific_name,
        tree_name:$tree_name,
        fruit_name:$fruit_name,
        family:$family,
        origin:$origin,
        description:$description,
        bloom:$bloom,
        maturation_fruit:$maturation_fruit,
        life_cycle:$life_cycle,
        climatic_zone:$climatic_zone
        ){
        id
        scientific_name
        tree_name
        family
        }
    }
`;
  

Define the function for handling the mutation:

    JavaScript
   
   const [addFruit,{data,loading,error}] = useMutation(newFruit);

Define the onSubmit function:

    JavaScript
   
 

   const onSubmit = e => {
    e.preventDefault();
    if(id && scientific_name && tree_name && fruit_name && family && origin && description && bloom && maturation_fruit && life_cycle && climatic_zone){
        addFruit({variables:{
        id,scientific_name,tree_name,fruit_name,family,origin,description,bloom,maturation_fruit,life_cycle,climatic_zone
        }});
        if(!loading && !error){
        setMessage("Fruit added successfully");
        console.log("data ",data);
        setId('');
        setScientificName('');
        setTreeName('');
        setFruitName('');
        setFamily('');
        setOrigin('');
        setDescription('');
        setBloom('');
        setMaturationFruit('');
        setLifeCycle('');
        setClimaticZone('');
        }
    }else{
    setFormError('All fields are required');
    return;
    }
}
  

Render the form view:

    JSX
   
 

   return (
    <Layout>
    <div className='form-container'>
        <form onSubmit={onSubmit}>
        {
            formError && (
            <div className='form-body'>
                <div className='error'>
                <p>{formError}</p>
                </div>
            </div>
            )
        }
        {
            error && (
            <div className='form-body'>
                <div className='error'>
                <p>{formError}</p>
                </div>
            </div>
            )
        }
        {
            message && (
            <div className='form-body'>
                <div className='message'>
                <p>{message}</p>
                </div>
            </div>
            )
        }
        <div className='form-body'>
            <label>ID</label>
            <input type="text" className='form-control' onChange={e => setId(e.target.value)} value={id} placeholder="Fruit ID"/>
        </div>
        <div className='form-body'>
            <label>Scientific Name</label>
            <input type="text" className='form-control' onChange={e => setScientificName(e.target.value)} value={scientific_name} placeholder="Fruit Scientific Name"/>
        </div>
        <div className='form-body'>
            <label>Tree Name</label>
            <input type="text" className='form-control' onChange={e => setTreeName(e.target.value)} value={tree_name} placeholder="Fruit Tree Name"/>
        </div>
        <div className='form-body'>
            <label>Fruit Name</label>
            <input type="text" className='form-control' onChange={e => setFruitName(e.target.value)} value={fruit_name} placeholder="Fruit Name"/>
        </div>
        <div className='form-body'>
            <label>Fruit Family</label>
            <input type="text" className='form-control' onChange={e => setFamily(e.target.value)} value={family} placeholder="Fruit Family"/>
        </div>
        <div className='form-body'>
            <label>Fruit Origin</label>
            <input type="text" className='form-control' onChange={e => setOrigin(e.target.value)} value={origin} placeholder="Fruit Origin"/>
        </div>
        <div className='form-body'>
            <label>Fruit Description</label>
            <input type="text" className='form-control' onChange={e => setDescription(e.target.value)} value={description} placeholder="Fruit Description"/>
        </div>
        <div className='form-body'>
            <label>Fruit Bloom</label>
            <input type="text" className='form-control' onChange={e => setBloom(e.target.value)} value={bloom} placeholder="Fruit Bloom"/>
        </div>
        <div className='form-body'>
            <label>Fruit Maturation Fruit</label>
            <input type="text" className='form-control' onChange={e => setMaturationFruit(e.target.value)} value={maturation_fruit} placeholder="Fruit Maturation Fruit"/>
        </div>
        <div className='form-body'>
            <label>Fruit Life Cycle</label>
            <input type="text" className='form-control' onChange={e => setLifeCycle(e.target.value)} value={life_cycle} placeholder="Fruit Life Cycle"/>
        </div>
        <div className='form-body'>
            <label>Fruit Climatic Zone</label>
            <input type="text" className='form-control' onChange={e => setClimaticZone(e.target.value)} value={climatic_zone} placeholder="Fruit Climatic Zone"/>
        </div>
        <div className='form-body'>
            <button type="submit">{
            loading ? "Loading..." : "Submit"
            }</button>
        </div>
        </form>
    </div>
    </Layout>
)
  

From your web page, click on add fruit link on the navbar:

On your fruit's page, you should have a new entry on your app as follows:

Conclusion

Now you have mastered consuming GraphQL API with React.js. I hope you love it!

API GraphQL Data (computing) React (JavaScript library)

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