I found the barrier to entry was unnecessarily frustrating due to the lack of a _good_ beginners tutorial calling out common pitfalls. But don’t let this sway you, because once you move past this, it is really fun.

Here are the things they don’t tell you about getting started.

1. You should download the basic examples zip from the their site.
2. You’ll want to grab the processing.init.js and the processing.js from the zip or tarball to include on your page.
3. As you begin coding you must tag any processing.js script on your page with <script type=“application/processing”>//your script here</script>
4. You must have a corresponding <canvas width=“200px” height=“200px”></canvas> tag after your script in order for it to render the drawing. Make height and width whatever size you’d like.
5. Another note is that you can have multiple canvases on your page, you’re not limited to one.
6. The processing.init.js looks for <script type=“application/processing”></script> tag on your page and performs the processing.js initialization, if you don’t have this included on your page nothing will be drawn.
7. An alternative to using the processing.init.js and <script type=”application/processing”></script> is to use the datasrc attribute on the canvas tag. <canvas datasrc=”your_processing_script.js”></canvas>

These are just some of the things I ran into and I hope this helps anyone trying to get started with processsing.js. Next time I will post something using the processing.js library.

1.) Rails now has seeding functionality and along with it comes a new task, db:seed. If you use the seed_fu gem be aware that your db:seed call that worked with the gem is now executing the Rails version of db:seed. You will need to call rake db:seed_fu to get the gem version to work.

2.) ActiveSupport::JSON::ParseError no longer exists, so be sure to use ActiveSupport::JSON.parse_error.

3.) Update your rspec and rspec-rails gems to 1.3.x.

4.) Update your rack gem from 1.0.0 to 1.0.1

5.) Rails 2.3.5 works with the RailsXss plugin, in Rails 3 escaping content in erb will default, but if you want to ensure your site isn’t at risk of XSS, make sure you do this install.

Jruby upgrade notes:

If you are using Jruby < 1.4 and you use the net/http library, you better upgrade soon. We were having all sorts of problems with threading and exorbitantly long running requests. There were several bug fixes around the open and read timeout functionality in Jruby 1.4. Now network requests will timeout properly according to your open and read timeout settings.