In this new post to the Web Mozarts site, Bernhard talks about the architecture behind the current Symfony2 forms implementation and how it handles the requests your forms make.

Symfony2 features a brand-new Form component that, to my knowledge, supersedes most existing PHP form libraries in functionality and extensibility (not counting the still lacking, native JavaScript support). [...] The purpose of this post is to demonstrate that the Symfony2 Form component is perfectly suited for this requirement. Symfony2-specific functionality can be unplugged, leaving only the raw core dealing with form processing and abstraction.

The post is broken up into several different sections, each detailing a different aspect of this Forms functionality:

• It's influences from other frameworks
• Key aspects it provides
• Abstraction (reusable code)
• Extensibility
• Compositionality
• Separation of Concerns
• Model Binding
• Dynamic Behavior

Both a high-level architecture and low-level architecture are provided, showing you the internal flow behind the form handling. You can find out more about this component in the Symfony manual or peek into the code on github.