React Native Fetch – To make HTTP API call in React Native

React Native Fetch

This post will give you an idea about how to Make HTTP Request to Fetch the Data From Web APIs in React Native. Here is an interesting example of posting and fetching the data from the server. Whenever you connect your application from the backend server (to get or post the data) you have to make an HTTP  request. Here we will show you how to perform network tasks in React Native.

Code Snippet of Basic Network Call using Fetch

fetch('Web URL HERE', {
    method: 'GET'
    //Request Type 
})
.then((response) => response.json())
//If response is in json then in success
.then((responseJson) => {
    //Success 
    console.log(responseJson);
})
//If response is not in json then in error
.catch((error) => {
    //Error 
    console.error(error);
});

In the example below, we are using free demo APIs. The example has two-button each has its own onPress which triggers our services. Just for the demo purpose, we are using buttons to trigger the request but If You need any data which needs to render while loading your screen you can use componentDidMount lifecycle method to load the data from the server as soon as the component is mounted. So let’s get started.

To Make a React Native App

Getting started with React Native will help you to know more about the way you can make a React Native project. We are going to use react native command line interface to make our React Native App.

If you have previously installed a global react-native-cli package, please remove it as it may cause unexpected issues:

npm uninstall -g react-native-cli @react-native-community/cli

Run the following commands to create a new React Native project

npx react-native init ProjectName

If you want to start a new project with a specific React Native version, you can use the --version argument:

npx react-native init ProjectName --version X.XX.X

Note If the above command is failing, you may have old version of react-native or react-native-cli installed globally on your pc. Try uninstalling the cli and run the cli using npx.

This will make a project structure with an index file named App.js in your project directory.

Code

Open App.js in any code editor and replace the code with the following code

App.js

// React Native Fetch – To make HTTP API call in React Native
// https://aboutreact.com/react-native-http-networking/

// import React in our code
import React from 'react';

// import all the components we are going to use
import {
  SafeAreaView,
  StyleSheet,
  View,
  TouchableOpacity,
  Text,
} from 'react-native';

const App = () => {
  const getDataUsingGet = () => {
    //GET request
    fetch('https://jsonplaceholder.typicode.com/posts/1', {
      method: 'GET',
      //Request Type
    })
      .then((response) => response.json())
      //If response is in json then in success
      .then((responseJson) => {
        //Success
        alert(JSON.stringify(responseJson));
        console.log(responseJson);
      })
      //If response is not in json then in error
      .catch((error) => {
        //Error
        alert(JSON.stringify(error));
        console.error(error);
      });
  };

  const getDataUsingPost = () => {
    //POST json
    var dataToSend = {title: 'foo', body: 'bar', userId: 1};
    //making data to send on server
    var formBody = [];
    for (var key in dataToSend) {
      var encodedKey = encodeURIComponent(key);
      var encodedValue = encodeURIComponent(dataToSend[key]);
      formBody.push(encodedKey + '=' + encodedValue);
    }
    formBody = formBody.join('&');
    //POST request
    fetch('https://jsonplaceholder.typicode.com/posts', {
      method: 'POST', //Request Type
      body: formBody, //post body
      headers: {
        //Header Defination
        'Content-Type': 
          'application/x-www-form-urlencoded;charset=UTF-8',
      },
    })
      .then((response) => response.json())
      //If response is in json then in success
      .then((responseJson) => {
        alert(JSON.stringify(responseJson));
        console.log(responseJson);
      })
      //If response is not in json then in error
      .catch((error) => {
        alert(JSON.stringify(error));
        console.error(error);
      });
  };

  return (
    <SafeAreaView style={{flex: 1}}>
      <View style={styles.container}>
        <View style={styles.container}>
          {/*Running GET Request*/}
          <TouchableOpacity
            style={styles.buttonStyle}
            onPress={getDataUsingGet}>
            <Text style={styles.textStyle}>
              Get Data Using GET
            </Text>
          </TouchableOpacity>
          {/*Running POST Request*/}
          <TouchableOpacity
            style={styles.buttonStyle}
            onPress={getDataUsingPost}>
            <Text style={styles.textStyle}>
              Get Data Using POST
            </Text>
          </TouchableOpacity>
        </View>
        <Text
          style={{
            fontSize: 18,
            textAlign: 'center',
            color: 'grey'
          }}>
          React Native Fetch
        </Text>
        <Text
          style={{
            fontSize: 16,
            textAlign: 'center',
            color: 'grey'
          }}>
          www.aboutreact.com
        </Text>
      </View>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'white',
    justifyContent: 'center',
    padding: 20,
  },
  textStyle: {
    fontSize: 18,
    color: 'white',
  },
  buttonStyle: {
    alignItems: 'center',
    backgroundColor: '#f4511e',
    padding: 10,
    marginVertical: 10,
  },
});

export default App;

To Run the React Native App

Open the terminal again and jump into your project using.

cd ProjectName

1. Start Metro Bundler

First, you will need to start Metro, the JavaScript bundler that ships with React Native. To start Metro bundler run following command:

npx react-native start

Once you start Metro Bundler it will run forever on your terminal until you close it. Let Metro Bundler run in its own terminal. Open a new terminal and run the application.

2. Start React Native Application

To run the project on an Android Virtual Device or on real debugging device:

npx react-native run-android

or on the iOS Simulator by running (macOS only)

npx react-native run-ios

Output Screenshots

Output in Online Emulator

This is how you can Make HTTP Request to Fetch the data from Web APIs in React Native. If you have any doubts or you want to share something about the topic you can comment below or contact us here. There will be more posts coming soon. Stay tuned!

Hope you liked it. 🙂