API Development (RESTful API)

Example Code

<?php

// Set Content-Type header for JSON responses
header("Content-Type: application/json");

// Define the data storage file (for simplicity, using a JSON file instead of a DB)
$dataFilePath = 'items.json';

// --- Helper Functions ---

// Read all items from the JSON file
function readItems($filePath) {
    if (!file_exists($filePath) || filesize($filePath) == 0) {
        return [];
    }
    $json = file_get_contents($filePath);
    return json_decode($json, true) ?: [];
}

// Write items to the JSON file
function writeItems($filePath, $items) {
    file_put_contents($filePath, json_encode($items, JSON_PRETTY_PRINT));
}

// Generate a unique ID for new items
function generateId($items) {
    return empty($items) ? 1 : max(array_column($items, 'id')) + 1;
}

// --- Main API Logic ---

// Get the HTTP method and request URI components
$method = $_SERVER['REQUEST_METHOD'];
// Example URI: /api.php/items/1
// This simplistic routing assumes `api.php` is accessed directly and path info is used.
$requestUri = explode('/', trim($_SERVER['REQUEST_URI'], '/'));
$scriptName = basename($_SERVER['SCRIPT_NAME']);

// Find the base position of the script name in the URI parts
$scriptIndex = array_search($scriptName, $requestUri);
if ($scriptIndex !== false) {
    $requestUri = array_slice($requestUri, $scriptIndex + 1);
}

$resource = isset($requestUri[0]) ? $requestUri[0] : ''; // e.g., 'items'
$id = isset($requestUri[1]) && is_numeric($requestUri[1]) ? (int)$requestUri[1] : null; // e.g., '1'

// Simulate routing for '/items' resource
if ($resource !== 'items') {
    http_response_code(404);
    echo json_encode(['message' => 'Resource not found']);
    exit();
}

$items = readItems($dataFilePath);

switch ($method) {
    case 'GET':
        if ($id !== null) {
            // GET /items/{id} - Retrieve a single item
            $item = array_filter($items, function($item) use ($id) {
                return $item['id'] == $id;
            });
            $item = reset($item); // Get the first (and only) matched item

            if ($item) {
                http_response_code(200);
                echo json_encode($item);
            } else {
                http_response_code(404);
                echo json_encode(['message' => 'Item not found']);
            }
        } else {
            // GET /items - Retrieve all items
            http_response_code(200);
            echo json_encode($items);
        }
        break;

    case 'POST':
        // POST /items - Create a new item
        $data = json_decode(file_get_contents('php://input'), true);

        if (!isset($data['name']) || !isset($data['description'])) {
            http_response_code(400);
            echo json_encode(['message' => 'Missing required fields (name, description)']);
            exit();
        }

        $newItem = [
            'id' => generateId($items),
            'name' => $data['name'],
            'description' => $data['description'],
            'created_at' => date('Y-m-d H:i:s')
        ];

        $items[] = $newItem;
        writeItems($dataFilePath, $items);

        http_response_code(201); // Created
        echo json_encode($newItem);
        break;

    case 'PUT':
        // PUT /items/{id} - Update an existing item
        if ($id === null) {
            http_response_code(400);
            echo json_encode(['message' => 'Item ID is required for PUT request']);
            exit();
        }

        $data = json_decode(file_get_contents('php://input'), true);
        $found = false;

        foreach ($items as &$item) {
            if ($item['id'] == $id) {
                $item['name'] = $data['name'] ?? $item['name'];
                $item['description'] = $data['description'] ?? $item['description'];
                $item['updated_at'] = date('Y-m-d H:i:s');
                $found = true;
                break;
            }
        }

        if ($found) {
            writeItems($dataFilePath, $items);
            http_response_code(200);
            echo json_encode(['message' => 'Item updated successfully', 'item' => $item]);
        } else {
            http_response_code(404);
            echo json_encode(['message' => 'Item not found']);
        }
        break;

    case 'DELETE':
        // DELETE /items/{id} - Delete an item
        if ($id === null) {
            http_response_code(400);
            echo json_encode(['message' => 'Item ID is required for DELETE request']);
            exit();
        }

        $initialCount = count($items);
        $items = array_filter($items, function($item) use ($id) {
            return $item['id'] != $id;
        });
        $items = array_values($items); // Re-index array after filtering

        if (count($items) < $initialCount) {
            writeItems($dataFilePath, $items);
            http_response_code(200); // Or 204 No Content for successful deletion without content
            echo json_encode(['message' => 'Item deleted successfully']);
        } else {
            http_response_code(404);
            echo json_encode(['message' => 'Item not found']);
        }
        break;

    default:
        // Method Not Allowed
        http_response_code(405);
        echo json_encode(['message' => 'Method Not Allowed']);
        break;
}

?>