1. happs intro
2. the missing happs documentation
3. getting started with happs
4. prerequisites
5. cabal install me
6. main
7. url handling
8. templates
9. stringtemplate basics
10. debugging
11. form data: get and post
12. form data: file uploads
13. cookies
14. introduction to macid
15. using macid safely
16. macid dummy data
17. macid updates and queries
18. changing the data model
19. macid stress test
20. limitations of macid
21. foreign characters
22. cron jobs
23. thanks
24. appendix (floundering in ghci)

Basic Request Handling in HAppS

One of the most basic functions of a web framework is to give you a way of controlling what happens when a web browser makes an http request.

Let's look at some simple examples.

1. Read the source code of the simpleHandlers function in ControllerBasic.hs to see how urls are handled in HAppS. Pay attention to the comments!
2. Follow the urls below by clicking on them. Match what happens when you click on a link with the code in ControllerBasic.hs

• introduction to handlers: hello world
• exactdir and msgToSp (subdirectories of the path argument do not match): exactdir-with-msgtosp ... exactdir-with-msgtosp/subdir ...
• introduction to dir and msgToSp -- subdirectories *do* match: dir-with-msgtosp ... dir-with-msgtosp/subdir
• gluing handlers together / handlers as monoids: handleraddition1 ... handleraddition2 ... handleraddition3 ... handleraddition4 ... handleraddition5
• the "empty" handler: nohandle1 ... nohandle2
• IO in the response: IO Response ... Another IO Response
• Formatted html: First attempt at formatted html (wrong)
• Second attempt at formatted html (right)
• Foreign characters in formatted html
• Serving static files: Using dir and fileserve "templates", we can view templates ... The template that was used to generate this page

The static file serving example above hints at the templating system used by this tutorial to put together web pages behind the scenes.

We learn about using templates with HAppS next.