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 init to make our React Native App. Assuming that you have node installed, you can use npm to install the react-native-cli command line utility. Open the terminal and go to the workspace and run

npm install -g react-native-cli

Run the following commands to create a new React Native project

react-native init ProjectName

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

react-native init ProjectName --version X.XX.X
react-native init ProjectName --version react-native@next

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

//This is an example code to understand HTTP Requests// 
import React, { Component } from 'react';
//import react in our code. 

import { StyleSheet, View, Button, Alert} from 'react-native';
//import all the components we are going to use. 

export default class App extends Component {

  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);
    });
  }

  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);
    });
  }
  render() {
    return (
      <View style={styles.MainContainer}>
        {/*Running GET Request*/}
        <Button title='Get Data Using GET' onPress={this.getDataUsingGet}/>
        {/*Running POST Request*/}
        <Button title='Get Data Using POST' onPress={this.getDataUsingPost}/>
      </View>
    );
  }
}
const styles = StyleSheet.create({
  MainContainer :{
    justifyContent: 'center',
    flex:1,
    margin: 10
  }
});

To Run the React Native App

Open the terminal again and jump into your project using.
cd ProjectName
To run the project on an Android Virtual Device or on real debugging device
react-native run-android
or on the iOS Simulator by running
react-native run-ios (macOS only).

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. 🙂


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5 thoughts on “React Native Fetch – To make HTTP API call in React Native”

  1. Hi, with the newer version of react-native I am getting [TypeError: Network request failed]. Have you encountered with this error? I was reading that react native has problem to connect to unsecured server, but mine is with official SSL licence.
    Many people were suggesting to modify Android manifest and add there android:usesCleartextTraffic=”true”, but I am working with expo so I don’t have access to those files. And probably it won’t solve issue in iOS side as well…

    Reply
    • Hey, I usually don’t work with expo as this behaves very different from the development after ejecting the project, I have also faced many issues with the web service calling and the integration of dependencies in the Expo and solved only after some hit and trials. In the metter of Expo, I can’t help you too much as the Expo that I have integrated into this post is working and you are facing the issue. :p

      Reply
  2. How to avoid ‘TypeError: Network request failed’ if user don’t connection to internet; when it’s obvious?
    How to make, instead of that, an alert appears notifying that, indeed, there is no internet ?

    Reply

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