Slim 4 - PostgreSQL database connection

1

I am using Slim 4 to build an API that will connect to a PostgreSQL 12 database and produce JSON objects.

To do this I am using the following skeleton with PHP 7.4.

I am looking for a simple, nice and correct way to connect to the database. I have been through a lot of tutorials but none of them explains the whole thing. I used to code PHP back in the dinosaurs era and gave up coding for 15 years. I have to admit that I am a bit lost with the dependencies and containers.

I am starting from scratch with the skeleton and I am very much open to any way establish the connection to the DB and use it in my routes.

My settings.php file looks like:

declare(strict_types=1);

use DI\ContainerBuilder;
use Monolog\Logger;

return function (ContainerBuilder $containerBuilder) {
    // Global Settings Object
    $containerBuilder->addDefinitions([
        'settings' => [
            'displayErrorDetails' => true, // Should be set to false in production
            'logger' => [
                'name' => 'slim-app',
                'path' => isset($_ENV['docker']) ? 'php://stdout' : __DIR__ . '/../logs/app.log',
                'level' => Logger::DEBUG,
            ],
            "db" => [
                "host" => "localhost",
                "dbname" => "mydatabase",
                "user" => "myuser",
                "pass" => "mypassword"
            ],
        ],
    ]);
};

My dependencies.php file looks like:

declare(strict_types=1);

use DI\ContainerBuilder;
use Monolog\Handler\StreamHandler;
use Monolog\Logger;
use Monolog\Processor\UidProcessor;
use Psr\Container\ContainerInterface;
use Psr\Log\LoggerInterface;


return function (ContainerBuilder $containerBuilder) {
    $containerBuilder->addDefinitions([
        LoggerInterface::class => function (ContainerInterface $c) {
            $settings = $c->get('settings');

            $loggerSettings = $settings['logger'];
            $logger = new Logger($loggerSettings['name']);

            $processor = new UidProcessor();
            $logger->pushProcessor($processor);

            $handler = new StreamHandler($loggerSettings['path'], $loggerSettings['level']);
            $logger->pushHandler($handler);

            return $logger;
        },

    ]);
    $containerBuilder->addDefinitions([
        PDO::class => function (ContainerInterface $c) {
            $settings = $c->get('settings');

            $dbSettings = $settings['db'];

            $pdo = new PDO("pgsql:host=" . $dbSettings['host'] . ";dbname=" . $dbSettings['dbname'], $dbSettings['user'], $dbSettings['pass']);
            $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
            return $pdo;
        },
    ]);

};

Here is the index.php file:

declare(strict_types=1);
use App\Application\Handlers\HttpErrorHandler;
use App\Application\Handlers\ShutdownHandler;
use App\Application\ResponseEmitter\ResponseEmitter;
use DI\ContainerBuilder;
use Slim\Factory\AppFactory;
use Slim\Factory\ServerRequestCreatorFactory;

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

// Instantiate PHP-DI ContainerBuilder
$containerBuilder = new ContainerBuilder();
if (false) { // Should be set to true in production
$containerBuilder->enableCompilation(__DIR__ . '/../var/cache');
}

// Set up settings
$settings = require __DIR__ . '/../app/settings.php';
$settings($containerBuilder);

// Set up dependencies
$dependencies = require __DIR__ . '/../app/dependencies.php';
$dependencies($containerBuilder);

// Set up repositories
$repositories = require __DIR__ . '/../app/repositories.php';
$repositories($containerBuilder);

// Build PHP-DI Container instance
$container = $containerBuilder->build();

// Instantiate the app
AppFactory::setContainer($container);
$app = AppFactory::create();
$callableResolver = $app->getCallableResolver();

// Register middleware
$middleware = require __DIR__ . '/../app/middleware.php';
$middleware($app);

// Register routes
$routes = require __DIR__ . '/../app/routes.php';
$routes($app);

/** @var bool $displayErrorDetails */
$displayErrorDetails = $container->get('settings')['displayErrorDetails'];

// Create Request object from globals
$serverRequestCreator = ServerRequestCreatorFactory::create();
$request = $serverRequestCreator->createServerRequestFromGlobals();

// Create Error Handler
$responseFactory = $app->getResponseFactory();
$errorHandler = new HttpErrorHandler($callableResolver, $responseFactory);

// Create Shutdown Handler
$shutdownHandler = new ShutdownHandler($request, $errorHandler, $displayErrorDetails);
register_shutdown_function($shutdownHandler);

// Add Routing Middleware
$app->addRoutingMiddleware();

// Add Error Middleware
$errorMiddleware = $app->addErrorMiddleware($displayErrorDetails, false, false);
$errorMiddleware->setDefaultErrorHandler($errorHandler);

// Run App & Emit Response
$response = $app->handle($request);
$responseEmitter = new ResponseEmitter();
$responseEmitter->emit($response);

And finally the routes.php file:

declare(strict_types=1);

use App\Application\Actions\User\ListUsersAction;
use App\Application\Actions\User\ViewUserAction;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\App;
use Slim\Interfaces\RouteCollectorProxyInterface as Group;

return function (App $app) {
    $app->get('/', function (Request $request, Response $response) {
        $response->getBody()->write('Hello world!');
        return $response;
    });

    $app->group('/users', function (Group $group) {
        $group->get('', ListUsersAction::class);
        $group->get('/{id}', ViewUserAction::class);
    });
};

I must have made mistakes in the code :slight_smile:

What I am missing is the way to connect to the database in the routes to collect the data.

Please note that the very reason why I am using a framework and a skeleton is because I am not very good at coding :slight_smile:

Thanks in advance for your answers