HELLO WORLD ONSLIM FRAMEWORK 3.X

Ryan Szrama (@ryanszrama)CTO, Commerce Guys

http://www.slimframework.com

“Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs.”

Created by Josh Lockhart (a.k.a. @codeguy),author of Modern PHP and PHP the Right Way.

http://www.phptherightway.com

A BRIEF HISTORY OF SLIM• Started as a learning experience /

tool for its creator. Sound familiar?

• Nov. 2, 2010 - Slim 1.0.0

• Sep. 9, 2012 - Slim 2.0.0

• @silentworks / @akrabat added as maintainers to grow its bus factor

• PHP-FIG accepts PSR-7 (HTTP Request / Response interfaces)

• July 2, 2015 - Slim 3.0.0-beta1

THE SLIM APPROACH

• Quickly define an application with all of its routes.

• Match incoming requests to routes that generate responses using PSR-7 request / response objects.

• Add application and route level “middleware” callbacks as LIFO / FILO stacks. #yolo

composer require slim/slim:3.x-dev

<?php

require 'vendor/autoload.php';

$app = new \Slim\App();

$app->get('/', function($request, $response, $args) { echo 'Hello, world!'; });

$app->run();

php -S localhost:8000

GROKKING THE ROUTE

• A route is a closure or callable with a signature that includes the request, response, and arguments. It MUST return a response object.

• Route closures are bound to the $app object.

• Output buffering captures all echoed output to be returned as the response body.

A BETTER ROUTE• Use the response object’s write method (and give

the route a name):

$app->get('/hello', function($request, $response, $args) {

$response->write('Hello, world!'); return $response;

})->setName('hello-world');

USING NAMED ARGUMENTS

• The Slim router extends FastRoute, which includes support for named arguments (e.g. node/%node).

• Curly braces denote an argument with support for optional matching via regular expressions.

• Arguments are passed to the route callback via the $args associative array.

<?php

require 'vendor/autoload.php';

$app = new \Slim\App();

$app->get('/hello/{name:[A-Za-z]+}', function($request, $response, $args) {

return $response->write('Hello, ' . $args['name'] . '!');

})->setName('hello-name');

$app->run();

GROKKING MIDDLEWARE

• Middleware is a callable added to the application and individual routes with a signature that includes the request, response, and next callable.

• Middleware MUST return a response object.

• Middleware MAY invoke the next callable in the stack and may execute more code after doing so.

$app->add(function ($request, $response, $next) {

$response->write('BEFORE'); $response = $next($request, $response); $response->write('AFTER');

return $response; });

$app->get('/', function ($request, $response, $args) {

echo ' Hello ';

});

LAYERING MIDDLEWARE• Use middleware to manage user sessions and

authentication, content negotiation, caching, etc.

(From http://stackphp.com.)

MANAGING DEPENDENCIES

• Slim uses the “Pimple” dependency injection container.

• Create the container and define the objects your application will depend on as services (e.g. a Twig environment or database connection).

• Construct the $app with yonder container and get dependencies as needed from it.

$container = new \Slim\Container();

$container['twig'] = function($container) {

$loader = new Twig_Loader_Filesystem('templates');

return new Twig_Environment($loader, array('cache'));

};

$app = new \Slim\App($container);

$app->get('/hello', function($request, $response, $args) {

// Remember, $this is the $app. $template = $this->getContainer()-> get(‘twig')->loadTemplate('index.html');

return $response->write($template-> render(['content' => 'Hello, world!’]));

})->setName('hello-world');

http://ryanszrama.com/topics/slim

Learning to develop with Slim 3.x helped me better understand essential concepts in Drupal 8.