Slim 4 Documentation

Welcome

Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs. At its core, Slim is a dispatcher that receives an HTTP request, invokes an appropriate callback routine, and returns an HTTP response. That's it.

What's the point?

Slim is an ideal tool to create APIs that consume, repurpose, or publish data. Slim is also a great tool for rapid prototyping. Heck, you can even build full-featured web applications with user interfaces. More importantly, Slim is super fast and has very little code.

At its core, Slim is a dispatcher that receives an HTTP request, invokes an appropriate callback routine, and returns an HTTP response. That's it.

You don't always need a kitchen-sink solution like [Symfony][symfony] or [Laravel][laravel]. These are great tools, for sure. But they are often overkill. Instead, Slim provides only a minimal set of tools that do what you need and nothing else.

How does it work?

First, you need a web server like Nginx or Apache. You should configure your web server so that it sends all appropriate requests to one "front-controller" PHP file. You instantiate and run your Slim app in this PHP file.

A Slim app contains routes that respond to specific HTTP requests. Each route invokes a callback and returns an HTTP response. To get started, you first instantiate and configure the Slim application. Next, you define your application routes. Finally, you run the Slim application. It's that easy. Here's an example application:

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

/**

• Instantiate App
• In order for the factory to work you need to ensure you have installed
• a supported PSR-7 implementation of your choice e.g.: Slim PSR-7 and a supported
• ServerRequest creator (included with Slim PSR-7) */ $app = AppFactory::create();

/**

• The routing middleware should be added earlier than the ErrorMiddleware
• Otherwise exceptions thrown from it will not be handled by the middleware */ $app->addRoutingMiddleware();

/**

• Add Error Middleware
• @param bool $displayErrorDetails -> Should be set to false in production
• @param bool $logErrors -> Parameter is passed to the default ErrorHandler
• @param bool $logErrorDetails -> Display error details in error log
• @param LoggerInterface|null $logger -> Optional PSR-3 Logger
• Note: This middleware should be added last. It will not handle any exceptions/errors
• for middleware added after it. */ $errorMiddleware = $app->addErrorMiddleware(true, true, true);

// Define app routes $app->get('/hello/{name}', function (Request $request, Response $response, $args) { $name = $args['name']; $response->getBody()->write("Hello, $name"); return $response; });

// Run app $app->run();

<figcaption>Figure 1: Example Slim application</figcaption>
</figure>

## Request and response

When you build a Slim app, you are often working directly with Request
and Response objects. These objects represent the actual HTTP request received
by the web server and the eventual HTTP response returned to the client.

Every Slim app route is given the current Request and Response objects as arguments
to its callback routine. These objects implement the popular [PSR-7](/docs/v4/concepts/value-objects.html) interfaces. The Slim app route can inspect
or manipulate these objects as necessary. Ultimately, each Slim app route
**MUST** return a PSR-7 Response object.

## Bring your own components

Slim is designed to play well with other PHP components, too. You can register
additional first-party components such as [Slim-Csrf][csrf], [Slim-HttpCache][httpcache],
or [Slim-Flash][flash] that build upon Slim's default functionality. It's also
easy to integrate third-party components found on [Packagist](https://packagist.org/).

## How to read this documentation

If you are new to Slim, I recommend you read this documentation from start
to finish. If you are already familiar with Slim, you can instead jump straight
to the appropriate section.

This documentation begins by explaining Slim's concepts and architecture
before venturing into specific topics like request and response handling,
routing, and error handling.

## Documentation License
<p style="text-align: left;">
    This website and documentation is licensed under a <a rel="license" href="https://creativecommons.org/licenses/by-nc-nd/4.0/">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>.
    

    <a rel="license" href="https://creativecommons.org/licenses/by-nc-nd/4.0/">
        
    </a>
</p>

[symfony]: https://symfony.com/
[laravel]: https://laravel.com/
[csrf]: https://github.com/slimphp/Slim-Csrf/
[httpcache]: https://github.com/slimphp/Slim-HttpCache
[flash]: https://github.com/slimphp/Slim-Flash
[eloquent]: https://laravel.com/docs/5.1/eloquent
[doctrine]: http://www.doctrine-project.org/projects/orm.html