Book excerpt: Practical Symfony 2 takes you through the process of building an application using the popular Symfony 2 PHP framework. While reading the book, you will build your own forum application, which makes you use every part of the framework. You will gain a strong understanding of the ins and outs of Symfony and what makes it so powerful. When you have finished the book, you will be able to build any application you want using the Symfony 2 framework. You will learn the basics of building your first Symfony page, using the Twig templating engine to style your page and getting the lowdown on Symfony's Controllers. You will use Doctrine to map a database to your project and learn how to query it for specific information. We also look at the essential topics of testing and security, using PHPUnit to set up tests, and learning how to validate input and to authenticate users. We close the book by looking at internationalization and translating your site to reach the most users. What you’ll learn How to build an application using the Symfony 2 framework The basics of the MVC-model (Model-View-Controller) What an ORM is and how to use Doctrine-ORM Using the Twig templating engine to make your life easier How to check if changes introduced new bugs, by using PHPUnit How to make your application faster, using caching strategies Who this book is for Practical Symfony 2 is written for PHP-developers, who want to know, what the Symfony 2 framework has to offer them. By putting theory to practice right away, you will get to know everything you need, while building your own forum software.