File Uploads in a REST API in PHP (source to accompany https://youtu.be/0C1s7E6-1mw)

index.php

<?php

declare(strict_types=1);

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

require dirname(__DIR__) . "/vendor/autoload.php";

$app = AppFactory::create();

$app->post('/api/images', function (Request $request, Response $response) {

    $files = $request->getUploadedFiles();

    if ( ! array_key_exists("file", $files)) {

        $response->getBody()->write(json_encode("'file' missing from request data"));

        return $response->withHeader("Content-type", "application/json")
                        ->withStatus(422);

    }

    $file = $files["file"];

    $error = $file->getError();

    if ($error !== UPLOAD_ERR_OK) {

        return $response->withStatus(422);

    }
    
    if ($file->getSize() > 1000000) {

        return $response->withStatus(422);

    }

    $media_types = ["image/png", "image/jpeg"];

    if ( ! in_array($file->getClientMediaType(), $media_types)) {

        return $response->withStatus(422);

    }

    try {

        $file->moveTo(dirname(__DIR__) . "/uploads/" . $file->getClientFilename());

        return $response->withStatus(201);

    } catch (Exception $e) {

        return $response->withStatus(500);

    }

});

$app->get("/api/images/{id}", function (Request $request, Response $response) {

    $path = dirname(__DIR__) . "/uploads/fish.png";

    $contents = file_get_contents($path);

    $response->getBody()->write($contents);

    return $response->withHeader("Content-type", "image/png");

});

$app->delete("/api/images/{id}", function (Request $request, Response $response) {

    $path = dirname(__DIR__) . "/uploads/fish.png";

    unlink($path);

    return $response;

});

$app->run();