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Symfony2 – Franz Jordán 2011
Without diving into too much detail, let's see this process in action. Suppose you want to add
a/contact page to your Symfony application. First, start by adding an entry for /contact to
your routing configuration file:
contact:
pattern: /contact
defaults: { _controller: AcmeDemoBundle:Main:contact }
This example uses YAML to define the routing configuration. Routing configuration can also be
written in other formats such as XML or PHP.
When someone visits the /contact page, this route is matched, and the specified controller is
executed. As you'll learn in the routing chapter, the AcmeDemoBundle:Main:contact string
is a short syntax that points to a specific PHP method contactAction inside a class
called MainController:
class MainController
{
public function contactAction()
{
return new Response('Contact us!');
}
}
In this very simple example, the controller simply creates a Response object with the HTML
"Contact us!". In the controller chapter, you'll learn how a controller can render
templates, allowing your "presentation" code (i.e. anything that actually writes out HTML) to live
in a separate template file. This frees up the controller to worry only about the hard stuff:
interacting with the database, handling submitted data, or sending email messages.
Symfony2: Build your App, not your Tools.
You now know that the goal of any app is to interpret each incoming request and create an
appropriate response. As an application grows, it becomes more difficult to keep your code
organized and maintainable. Invariably, the same complex tasks keep coming up over and over
again: persisting things to the database, rendering and reusing templates, handling form
submissions, sending emails, validating user input and handling security.
The good news is that none of these problems is unique. Symfony provides a framework full of
tools that allow you to build your application, not your tools. With Symfony2, nothing is imposed
on you: you're free to use the full Symfony framework, or just one piece of Symfony all by itself.
Standalone Tools: The Symfony2 Components
So what is Symfony2? First, Symfony2 is a collection of over twenty independent libraries that
can be used inside any PHP project. These libraries, called the Symfony2 Components, contain
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