Packing a Symfony full-stack Framework Application in one File -- Bootstrapping

The most common way to create a Symfony project is to start with the Symfony Standard Edition: it defines a sensible directory structure for your project and it make things a lot easier when someone want to take over an existing project as he knows where the templates, the controllers, or the configuration are stored. So, let’s start our journey with the Symfony Standard Edition:

$ composer.phar create-project -n symfony/framework-standard-edition se/ 2.3.0

From there, let’s remove a bunch of code to get the bare minimum of code needed to keep it working:

rm -rf LICENSE README.md UPGRADE* bin/ app/SymfonyRequirements.php \
       app/autoload.php app/bootstrap.php.cache app/AppCache.php app/check.php \
       app/console app/phpunit.xml.dist app/Resources src/ web/config.php \
       web/favicon.ico web/robots.txt web/apple-touch-icon.png web/app.php web/bundles/ \
       app/cache/* app/log/* .travis.yml app/.htaccess web/.htaccess

I’ve removed all those files and directories because there are not needed for the purpose of our challenge.

Next, let’s simplify the configuration and move everything into just one file:

# app/config/config_dev.yml
framework:
    secret:          $ecret
    router:
        resource: "%kernel.root_dir%/config/routing_dev.yml"
    form:            ~
    csrf_protection: ~
    validation:      { enable_annotations: true }
    templating:
        engines: ['twig']
    session:         ~
    fragments:       ~

The routing_dev.yml file has been emptied for now, and all other configuration files have been removed.

We can also remove most of the bundles from the application kernel class:

use Symfony\Component\HttpKernel\Kernel;
use Symfony\Component\Config\Loader\LoaderInterface;

class AppKernel extends Kernel
{
    public function registerBundles()
    {
        return array(
            new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
            new Symfony\Bundle\TwigBundle\TwigBundle(),
        );
    }

    public function registerContainerConfiguration(LoaderInterface $loader)
    {
        $loader->load(__DIR__.'/config/config_'.$this->getEnvironment().'.yml');
    }
}

We can also simplify the web/app_dev.php code:

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Debug\Debug;

require_once __DIR__.'/../vendor/autoload.php';
Debug::enable();

require_once __DIR__.'/../app/AppKernel.php';

$kernel = new AppKernel('dev', true);
$request = Request::createFromGlobals();
$response = $kernel->handle($request);
$response->send();
$kernel->terminate($request, $response);

The composer.json file can also be simplified:

{
    "name": "fabpot/onefile-challenge",
    "license": "MIT",
    "type": "project",
    "autoload": {
        "psr-0": { "": "src/" }
    },
    "require": {
        "php": ">=5.3.3",
        "symfony/symfony": "2.3.*"
    }
}

   /app/cache/*
   /app/logs/*
   /vendor/
   /composer.lock

Run composer again to remove all unneeded dependencies:

$ composer.phar update

After cleaning everything, here is the directory structure:

app/
??? AppKernel.php
??? cache
??? config
?   ??? config_dev.yml
?   ??? routing_dev.yml
??? logs
composer.json
vendor/
web/
??? app_dev.php

As you can see, we are now down to 5 files. And of course, you still have the full power of the full-stack framework (from the web profiler to the Twig templating system). Code for today is available on Github.

In the next post, I will write about the Kernel class and how it works.