PHP REST API Tutorial: Building a REST API in PHP Without a Framework

In this tutorial, you’ll learn how to create a REST API in PHP without using a framework. This approach is ideal for those who want a lightweight and straightforward solution for API development. Follow these steps to build a simple and functional REST API.

What Is a REST API?

A REST API (Representational State Transfer Application Programming Interface) enables communication between a client and a server through HTTP methods like GET, POST, PUT, and DELETE. REST APIs are widely used for web and mobile app development, allowing seamless data exchange.

Why Create a REST API Without a Framework?

Frameworks like Laravel or Symfony provide robust solutions for API development, but they come with added complexity. For small-scale projects or when you want to maintain full control over your code, creating a REST API without a framework can be a practical choice.

Steps to Build a REST API in PHP

Step 1: Set Up Your Environment

Before diving into coding, ensure your development environment is ready.

Install PHP: Make sure PHP is installed on your system. Use php -v in your terminal to check the version.
Set Up a Local Server: Use tools like XAMPP, WAMP, or the built-in PHP server (php -S localhost:8000).
Create a Project Folder: Organize your files. For example, create a folder named php-api to store your API code.

Step 2: Create the API Endpoint

An API endpoint is a URL that allows clients to interact with your API. Start by creating a basic structure:

Define the API entry point: Create a file named api.php in your project folder.
Set up routing: Use a $_SERVER global variable to handle different HTTP methods like GET, POST, PUT, and DELETE.

Here’s an example code snippet:

<?php  
header("Content-Type: application/json");  

$requestMethod = $_SERVER['REQUEST_METHOD'];  

switch ($requestMethod) {  
    case 'GET':  
        handleGetRequest();  
        break;  
    case 'POST':  
        handlePostRequest();  
        break;  
    default:  
        echo json_encode(["message" => "Method not allowed"]);  
        http_response_code(405);  
        break;  
}  

function handleGetRequest() {  
    echo json_encode(["message" => "This is a GET request"]);  
}  

function handlePostRequest() {  
    echo json_encode(["message" => "This is a POST request"]);  
}  
?>

Step 3: Connect to a Database

APIs often interact with databases to retrieve or store data. Let’s Connect to a MySQL database using PHP’s PDO (PHP Data Objects).

<?php  
function connectToDatabase() {  
    $host = 'localhost';  
    $db = 'example_db';  
    $user = 'root';  
    $pass = '';  

    try {  
        $pdo = new PDO("mysql:host=$host;dbname=$db", $user, $pass);  
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);  
        return $pdo;  
    } catch (PDOException $e) {  
        die(json_encode(["error" => "Database connection failed", "message" => $e->getMessage()]));  
    }  
}  
?>

Step 4: Add CRUD Operations

CRUD (Create, Read, Update, Delete) operations are the foundation of most APIs. Here’s how to implement them:

Create (POST): Add Data

function addData($pdo, $data) {  
    $sql = "INSERT INTO users (name, email) VALUES (:name, :email)";  
    $stmt = $pdo->prepare($sql);  
    $stmt->execute([":name" => $data['name'], ":email" => $data['email']]);  
    return ["message" => "Data added successfully"];  
}

Read (GET): Fetch Data

function fetchData($pdo) {  
    $sql = "SELECT * FROM users";  
    $stmt = $pdo->query($sql);  
    return $stmt->fetchAll(PDO::FETCH_ASSOC);  
}

Update (PUT): Modify Data

function updateData($pdo, $id, $data) {  
    $sql = "UPDATE users SET name = :name, email = :email WHERE id = :id";  
    $stmt = $pdo->prepare($sql);  
    $stmt->execute([":name" => $data['name'], ":email" => $data['email'], ":id" => $id]);  
    return ["message" => "Data updated successfully"];  
}

Delete (DELETE): Remove Data

function deleteData($pdo, $id) {  
    $sql = "DELETE FROM users WHERE id = :id";  
    $stmt = $pdo->prepare($sql);  
    $stmt->execute([":id" => $id]);  
    return ["message" => "Data deleted successfully"];  
}

Step 5: Test Your API

Use tools like Postman or cURL to test your API endpoints.

GET Request: http://localhost/php-api/api.php
POST Request: Send a JSON payload like {"name": "John Doe", "email": "john@example.com"}.
PUT and DELETE Requests: Include the resource ID and relevant data.

Example Use Case

Imagine a mobile app that requires user data. By creating a REST API, you can serve this data efficiently and securely, enabling features like user registration, updates, and more.

Benefits of a Custom REST API

Lightweight and faster compared to framework-based APIs.
Full control over implementation.
Tailored to specific project needs.

Conclusion

This tutorial provides a starting point for building a PHP REST API without using a framework. While frameworks can simplify large projects, custom APIs are ideal for lightweight solutions. Try enhancing this API with additional features like authentication, pagination, or logging.

What’s Next?

Ready to start building your own REST API?
Add authentication for secure API access.
Implement advanced features like pagination, filtering, or rate limiting.

Have questions about this tutorial? Leave a comment below or share your experiences with building APIs in PHP!

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