BarCamp DC: Alternative Web App Structure

Notes on the presentation:

• Web App Structure
  
  • HTTP is stateless
    
    • Programs tend to be stateless
      
    • Normally, each new requests starts the app from scratch, then you try to get everything back from a session
      
    
    
  
  
• There's an alternative: continuations
  
  • Instead of the program running to output HTML, halt, start again with a new request (rinse, repeat) ...
    
  • You freeze the whole context (the state), and then the user does the next step, and the system picks right back up at the point where it left off
    
    • This is implemented through co-routines
      
    
    
  
  

• Seaside!
  
  • Written in SmallTalk
    
    • Uses squeak (an OS in a box, seriously isolated)
      
    
    
  • Application framework (think rails)
    
  • No templating system -- write your template in smalltalk
    
  • Offers through the web development
    
  
  

• Uncommon Web
  
  • Use common lisp to handle continuations with a macro
    
  • Replay the source tree to a specific point
    
  
  

• Continuity
  
  • Do this stateful stuff in perl
    
  • Written by our presenter
    
  • Uses co-routines
    
  • "Sorry perl's so ugly, but I love it so much."
    
  • Big problems with bookmarking. Oh well.
    
  
  

Comments

[Matt Bowen]

Thanks for the presentation!The notes are up with minor changes. Thanks for a really excellent presentation -- it seriously energized me on a project I've had bouncing around my head for weeks.