The document discusses the essential features that a web framework should provide, including templating, dynamic content handling, user input management, and interactivity. It highlights Lift's view-first approach, using pure XHTML or HTML5 templates, and the use of 'snippets' for content transformation. Additionally, it emphasizes the importance of server-side behavior, real-time interaction through techniques like Comet, and the integration of functional and reactive programming with a persistence layer and REST support.

1. Scala & Lift
Sander Mak

2. What should a
webframework
do?

3. Webframeworks should
• Provide templating
• Show dynamic content
• Handle user input
• Abstract from request/response cycle?
• Be highly interactive?
Preferably concise, performant and secure

4. Webframeworkstemplating
Provide
should
• Lift is view-first
• Pure XHTML or HTML5 templates
• Embed and surround to compose pages
default.html with:
<lift:bind name=”content” />
signup.html with:
<lift:surround with=”default”
name=”content”>
... signup form ...
<lift:surround />

5. Webframeworks should
Show dynamic content
• Pure templates: no code in templates
Problem?

6. Snippets

7. Webframeworks should
Show dynamic content
• Snippets transform DOM to DOM
NodeSeq => NodeSeq
• Well-formed and sanitized transformation
• Use {request, session, database} state

8. Webframeworks should
Show dynamic content
• Snippets transform DOM to DOM
NodeSeq => NodeSeq
• Well-formed and sanitized transformation
• Use {request, session, database} state
Not MVC: menu
/index.xhtml date
content

9. Webframeworks should
Handle user input
• Add server-side behavior to DOM nodes
... with snippets
• Behavior captured in closures
... which are executed after submit
• Lift unifies ajax and traditional request/
response interaction, includes JavaScript DSL

11. Highly interactive

12. Comet
• ‘Reverse Ajax’: server push
• Realtime webapps

13. Actors

14. Actors
• Asynchronous
• Mailbox serializes messages Mailbox
Internal state
• Thread pooling executor
Actor
actor ! Message

15. The demo
Actor
ChatServer
CometActor CometActor CometActor
ChatClient ChatClient ChatClient
...
Browser Browser Browser
...

17. Scala + Lift =
Abstraction

18. Wiring
• Functional/reactive programming

19. What else?
• Persistence layer - Mapper & Record
• REST support - Expose APIs for webapps
• Lift Modules - User contributed