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Symfony2 – Franz Jordán 2011
The front controller, app.php, is executed and the "internal:" URL /hello/Ryan is routed
internally using the routing configuration. By using Apache mod_rewriterules, you can force
the app.php file to be executed without needing to specify it in the URL:
http://localhost/hello/Ryan
Though front controllers are essential in handling every request, you'll rarely need to modify or
even think about them. We'll mention them again briefly in the Environments section.
The Application (app) Directory
As you saw in the front controller, the AppKernel class is the main entry point of the
application and is responsible for all configuration. As such, it is stored in the app/ directory.
This class must implement two methods that define everything that Symfony needs to know
about your application. You don't even need to worry about these methods when starting -
Symfony fills them in for you with sensible defaults.
registerBundles(): Returns an array of all bundles needed to run the application
(see The Bundle System);
registerContainerConfiguration(): Loads the main application configuration
resource file (see the Application Configuration section).
In day-to-day development, you'll mostly use the app/ directory to modify configuration and
routing files in the app/config/ directory (see Application Configuration). It also contains the
application cache directory (app/cache), a log directory (app/logs) and a directory for
application-level resource files, such as templates (app/Resources). You'll learn more about
each of these directories in later chapters.
Autoloading
When Symfony is loading, a special file - app/autoload.php - is included. This file is
responsible for configuring the autoloader, which will autoload your application files from
the src/ directory and third-party libraries from the vendor/ directory.
Because of the autoloader, you never need to worry about
using include orrequire statements. Instead, Symfony2 uses the namespace of a class to
determine its location and automatically includes the file on your behalf the instant you need a
class.
The autoloader is already configured to look in the src/ directory for any of your PHP classes.
For autoloading to work, the class name and path to the file have to follow the same pattern:
Class Name:
Acme\HelloBundle\Controller\HelloController
Path:
src/Acme/HelloBundle/Controller/HelloController.php
Typically, the only time you'll need to worry about the app/autoload.php file is when you're
including a new third-party library in the vendor/ directory. For more information on
autoloading, see How to autoload Classes.
The Source (src) Directory
Put simply, the src/ directory contains all of the actual code (PHP code, templates,
configuration files, stylesheets, etc) that drives your application. When developing, the vast
majority of your work will be done inside one or more bundles that you create in this directory.
But what exactly is a bundle?
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