How to make a Post request from frontend in react-native ?
The POST method is used to send data to the server to create a new resource or modify an existing resource on the server. We cannot make a POST request by using a web browser, as web browsers only directly support GET requests.
But what if we want to develop an application where we need to add some data to the backend or modify existing data whenever the user clicks a button from the UI side? In that case, we have to make a post request from the frontend (For example, on click of a button)
For learning purposes, we generally use tools such as Advanced Rest Client or Postman to create or add new data.
Generally, whenever an API is triggered from the browser, a GET request is sent, and the data is fetched.
Approach
In this article, we will see how to make post requests in react native. We will trigger an API using the fetch method on the click of a button, and after getting a response from that API, we will show an Alert message. To trigger a Post request from the UI side in react -native, we can send the Request option as a second Parameter.
Making POST requests from the frontend involves sending data to a backend API. React Native offers built-in support with fetch() or axios libraries. To give you a better idea of what we’re going to create, let’s watch a demo video.
Demo Video
Step-by-Step Implementation
Step 1: Create a React Native Project
Now, create a project with the following command.
npx create-expo-app app-name --template
Note: Replace the app-name with your app name for example : react-native-demo-app
Next, you might be asked to choose a template. Select one based on your preference as shown in the image below. I am selecting the blank template because it will generate a minimal app, as clean as an empty canvas in JavaScript.
It completes the project creation and displays a message: "Your Project is ready!" as shown in the image below.
Now go into your project folder, i.e., react-native-demo
cd app-nameProject Structure:
Step 2: Run Application
Start the server by using the following command.
npx expo startThen, the application will display a QR code.
- For the Android users,
- For the Android Emulator, press "a" as mentioned in the image below.
- For the Physical Device, download the "Expo Go" app from the Play Store. Open the app, and you will see a button labeled "Scan QR Code." Click that button and scan the QR code; it will automatically build the Android app on your device.
- For iOS users, simply scan the QR code using the Camera app.
- If you're using a web browser, it will provide a local host link that you can use as mentioned in the image below.
Step 3: Create a new component folder (optional)
You can create a new folder called "components" to organize all component files better, as mentioned in the image below. Alternatively, you can write the component code directly in App.js.
Step 4: Working with PostRequestExample.js
- Import libraries: Import required libraries at the top of the file.
import React from "react"; // Import React library for building UI components
import {
View, // Import View component for layout
StyleSheet, // Import StyleSheet for styling
Alert // Import Alert for displaying alerts
} from 'react-native';
import { Button } from "react-native-paper"; // Import Button component from react-native-paper library
- StyleSheet: Create a StyleSheet to style components like the btn.
// Define styles for the component
const styles = StyleSheet.create({
btn: {
marginTop: 60, // Add top margin
marginHorizontal: 30 // Add horizontal margin
}
});
- Button: This component is used to trigger the postExample function when the user taps on the button.
<Button
mode="contained"
onPress={postExample}
>
Click to make a Post request
</Button>
- postExample: This function is used to make a POST request.
// Function to make a POST request
const postExample = async () => {
try {
// Make a POST request to the API endpoint
const response = await fetch('https://reqres.in/api/posts', {
method: 'POST', // Specify HTTP method as POST
headers: {
'Content-Type': 'application/json', // Set content type to JSON
'x-api-key': 'reqres-free-v1' // Add API key in the headers
},
body: JSON.stringify({ postName: 'React updates' }) // Send data in the request body
});
// Parse the JSON response
const data = await response.json();
if (response.ok) { // Check if the response status is OK (200-299)
console.log(data); // Log the response data to the console
Alert.alert("Post created at:", data.createdAt || "No timestamp"); // Show success alert with timestamp
} else {
console.error(data); // Log the error response to the console
Alert.alert("Error", data.error || "Request failed"); // Show error alert
}
} catch (error) { // Catch any errors during the request
console.error(error); // Log the error to the console
Alert.alert("Error", "Something went wrong."); // Show generic error alert
}
};
- App Component: Wrap the Button with a View and return that inside the App function to render and place the postExample inside the App function, also make sure to export the App.
// Define the PostRequestExample functional component
const PostRequestExample = () => {
// Function to make a POST request
const postExample = async () => {
try {
// Make a POST request to the API endpoint
const response = await fetch('https://reqres.in/api/posts', {
method: 'POST', // Specify HTTP method as POST
headers: {
'Content-Type': 'application/json', // Set content type to JSON
'x-api-key': 'reqres-free-v1' // Add API key in the headers
},
body: JSON.stringify({ postName: 'React updates' }) // Send data in the request body
});
// Parse the JSON response
const data = await response.json();
if (response.ok) { // Check if the response status is OK (200-299)
console.log(data); // Log the response data to the console
Alert.alert("Post created at:", data.createdAt || "No timestamp"); // Show success alert with timestamp
} else {
console.error(data); // Log the error response to the console
Alert.alert("Error", data.error || "Request failed"); // Show error alert
}
} catch (error) { // Catch any errors during the request
console.error(error); // Log the error to the console
Alert.alert("Error", "Something went wrong."); // Show generic error alert
}
};
// Render the UI
return (
<View style={styles.btn}> {/* Apply styles to the container */}
{/* Button to trigger the POST request */}
<Button mode="contained" onPress={postExample}>
Click to make a Post request
</Button>
</View>
);
};
// Export the component for use in other files
export default PostRequestExample;
PostRequestExample.js:
import React from "react"; // Import React library for building UI components
import {
View, // Import View component for layout
StyleSheet, // Import StyleSheet for styling
Alert // Import Alert for displaying alerts
} from 'react-native';
import { Button } from "react-native-paper"; // Import Button component from react-native-paper library
// Define the PostRequestExample functional component
const PostRequestExample = () => {
// Function to make a POST request
const postExample = async () => {
try {
// Make a POST request to the API endpoint
const response = await fetch('https://reqres.in/api/posts', {
method: 'POST', // Specify HTTP method as POST
headers: {
'Content-Type': 'application/json', // Set content type to JSON
'x-api-key': 'reqres-free-v1' // Add API key in the headers
},
body: JSON.stringify({ postName: 'React updates' }) // Send data in the request body
});
// Parse the JSON response
const data = await response.json();
if (response.ok) { // Check if the response status is OK (200-299)
console.log(data); // Log the response data to the console
Alert.alert("Post created at:", data.createdAt || "No timestamp"); // Show success alert with timestamp
} else {
console.error(data); // Log the error response to the console
Alert.alert("Error", data.error || "Request failed"); // Show error alert
}
} catch (error) { // Catch any errors during the request
console.error(error); // Log the error to the console
Alert.alert("Error", "Something went wrong."); // Show generic error alert
}
};
// Render the UI
return (
<View style={styles.btn}> {/* Apply styles to the container */}
{/* Button to trigger the POST request */}
<Button mode="contained" onPress={postExample}>
Click to make a Post request
</Button>
</View>
);
};
// Export the component for use in other files
export default PostRequestExample;
// Define styles for the component
const styles = StyleSheet.create({
btn: {
marginTop: 60, // Add top margin
marginHorizontal: 30 // Add horizontal margin
}
});
Step 5: Working with App.js
Now call this PostRequestExample Component in the main "App" Component in App.js.
App.js:
import React from 'react';
import { View } from 'react-native';
import PostRequestExample from './components/PostRequestExample';
const App = () => {
return (
<View>
<PostRequestExample />
</View>
);
};
export default App;
Or
You can write the whole code in one file, i.e, App.js.
Complete Source Code:
App.js:
import React from "react"; // Import React library for building UI components
import {
View, // Import View component for layout
StyleSheet, // Import StyleSheet for styling
Alert // Import Alert for displaying alerts
} from 'react-native';
import { Button } from "react-native-paper"; // Import Button component from react-native-paper library
// Define the PostRequestExample functional component
const PostRequestExample = () => {
// Function to make a POST request
const postExample = async () => {
try {
// Make a POST request to the API endpoint
const response = await fetch('https://reqres.in/api/posts', {
method: 'POST', // Specify HTTP method as POST
headers: {
'Content-Type': 'application/json', // Set content type to JSON
'x-api-key': 'reqres-free-v1' // Add API key in the headers
},
body: JSON.stringify({ postName: 'React updates' }) // Send data in the request body
});
// Parse the JSON response
const data = await response.json();
if (response.ok) { // Check if the response status is OK (200-299)
console.log(data); // Log the response data to the console
Alert.alert("Post created at:", data.createdAt || "No timestamp"); // Show success alert with timestamp
} else {
console.error(data); // Log the error response to the console
Alert.alert("Error", data.error || "Request failed"); // Show error alert
}
} catch (error) { // Catch any errors during the request
console.error(error); // Log the error to the console
Alert.alert("Error", "Something went wrong."); // Show generic error alert
}
};
// Render the UI
return (
<View style={styles.btn}> {/* Apply styles to the container */}
{/* Button to trigger the POST request */}
<Button mode="contained" onPress={postExample}>
Click to make a Post request
</Button>
</View>
);
};
// Define styles for the component
const styles = StyleSheet.create({
btn: {
marginTop: 60, // Add top margin
marginHorizontal: 30 // Add horizontal margin
}
});
// Main App component
const App = () => {
return (
<View>
<PostRequestExample />
</View>
);
};
// Export the App component as default
export default App;
