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Describe how you would implement pagination in Slim Framework.

Describe how you would implement pagination in Slim Framework.

To implement pagination in Slim Framework, you can follow these steps:

Step 1: Set up a GET route for the paginated data

Define a route that accepts page numbers as a query parameter or a route parameter. This route will fetch and return the paginated data.

Example

<?php
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\Factory\AppFactory;

require __DIR__ . '/vendor/autoload.php';

$app = AppFactory::create();

$app->get('/items', function (Request $request, Response $response) {
    // Step 2: Fetch the page number from query parameters (or set default to 1)
    $queryParams = $request->getQueryParams();
    $page = isset($queryParams['page']) ? (int)$queryParams['page'] : 1;
    $perPage = 5; // Number of items per page

    // Step 3: Simulate a data source (e.g., an array of items)
    $items = range(1, 100); // Example data
    $totalItems = count($items);

    // Step 4: Calculate pagination offsets
    $offset = ($page - 1) * $perPage;
    $paginatedItems = array_slice($items, $offset, $perPage);

    // Step 5: Create a response with the paginated data
    $pagination = [
        'current_page' => $page,
        'per_page' => $perPage,
        'total_items' => $totalItems,
        'total_pages' => ceil($totalItems / $perPage),
        'data' => $paginatedItems
    ];

    $response->getBody()->write(json_encode($pagination));
    return $response->withHeader('Content-Type', 'application/json');
});

$app->run();
?>

Step 2: Fetch the page number

In the route, retrieve the page number from the query parameters (e.g., ?page=2). If no page is specified, default to page 1.

Step 3: Simulate or fetch data

For the purpose of this example, an array of numbers (1 to 100) is used as the data source. In a real application, you’d query a database or external API to fetch the data.

Step 4: Calculate the pagination offsets

Using the page number, calculate the offset for slicing the data and limit the number of items returned based on the perPage value.

Step 5: Return paginated data

Return the paginated data along with pagination metadata (e.g., current_page, total_items, total_pages, etc.) as a JSON response.

Step 6: Test the Pagination

Start your Slim app and test the pagination by calling the /items?page=1 route with different page numbers.

This simple approach can be expanded to handle larger data sets and more complex data retrieval methods (like using a database).