This repo contains the presentation that I did for erlangdc 2011. The goal is a $0.25 tour of Webmachine in 30min.

Presentation.

The presentation dir holds the src orgmode file used to generate the s5 html.

The following is the ‘org-publish-project-alist that I used to generate the html. If you want to edit the presentation you will have to

1. adjust paths accordingly
2. eval the following project-alist in your emacs
3. open presentation/erlangdc.org
4. edit
5. C-c C-e P (publish)

The new erlangdc.html file can be found in presentation/html/

(setq org-publish-project-alist
      '(("erlangdc"
         :publishing-directory "~/prj/erlangdc/presentation/html"
         :base-directory "~/prj/erlangdc/presentation/"
         :publishing-function org-publish-org-to-html
         :org-export-html-preamble "<div class='layout'><div id='controls'></div><div id='currentSlide'></div><div id='header'>%s</div><div id='footer'>%s</div></div><div class='presentation'><div class='slide front'>  <div id='front-logo'></div><h1 class='front'></h1><h3></h3></div>"
         :org-export-html-postamble "</div>"
         :sub-superscript nil
         )))

Webmachine Demo

the webmachine app in speakers dir is a simple json demo. The goal is to provide as simple of a demo as possible. I wanted to demonstrate

• GET a single resource
• GET a list of resources
• PUT a resource
• DELETE a resource
• GET on calculated data that is more than just data storage

speakers_resource.erl

This is the generated resource, about as simple as it gets.

speakers_ro.erl Read Only

This resource demos reading data from a very primitive data model. It shows how the following work

• use paths in dispatch.conf
• named variables in dispatch.conf
• properly provide json data
• use resource_exists/2 to provide 404
• build and send json data

speakers_rw.erl Read Write

This resource adds the ability to PUT data and DELETE a resource.

• edit allowed_methods/2 to accept PUT and DELETE
• content_types_accepted/2 to accept json data
• use malformed_request/2 to validate data
• delete_resource/2 to delete data

speakers_status.erl Status

This resource returns a list of paths based on status of the speaker.

It is intended as an example of calculating data. In other words something more than just writing and fetching to a db.

starting

simply cd into the speakers dir and run start.sh

tracing

to enable tracing you need to add the path in the dispatcher. I provided a shortcut in the speakers module.

on the prompt provided by start.sh type the following to enable tracing

speakers:trace().

Then visit http://localhost:8000/wmtrace