Common Dream

Introducing BGNow, Our Hack Days Project

Last week we had our inaugural Gnoso Hack Days. The general gist was take 2 days, work on whatever you want, and demo at 4 PM on the second day. Ethan (esmullis on Twitter) and I decided to do a diabetes related hack that we'd thought about for a while, and we wanted to make sure that we could actually release something at the end of the hack days.

The #bgnow Hash Tag

Tons of people touched by diabetes tweet their blood glucose number and include the hash tag #bgnow in the tweet. Those tweets are amazing to read, because they tell you about how diabetes touches so many normal aspects of peoples' lives. I've been following the search for #bgnow on Twitter for quite some time, but wanted some way to give back to the community that makes those posts.

Introducing BGNow


Our project, called BGNow and hosted at http://bgnow.logforlife.com, is an app that monitors Twitter for tweets including the #bgnow hash tag and then displays those tweets on a graph. The home page of BGNow shows all of the recent #bgnow tweets for all users and a graph for all users. We're using the same graphing technology that we used in Log for Life, but made the graph point hovers a bit more tweet-like by including the user's Twitter username and their profile picture. We wanted to allow users to focus on themselves, though, so you can also search for your Twitter username and see a page focused only on the #bgnow tweets that you've made.

We wrote the app in 33 hours, so things are probably far from perfect. Drop us an email at bgnow@logforlife.com if you notice any bugs or have any improvements you'd like to see.

Our next hack days will be in August, and I can't wait!

Serving Static Files With Sinatra on IronRuby

I've been using IronRuby a bit during the day at work, and yesterday I ran into a pretty curious issue. When running Sinatra 1.0 under IronRuby 1.0, I saw an exception like:

Can't convert string into fixnum

while trying to access static files. The workaround took me a while, so I wanted to post it here. First, though, a bit of background on the issue.

I'm not sure what's happening, but something strange is going on when you create a new class that inherits from the File class, like the StaticFile class in Sinatra does. For some reason, it looks like when File is subclassed its open method reverts to the implementation from the IO class. Here's some sample console output from MRI to show how things should behave:

Here's what happens in IronRuby:

Something terribly odd is happening there, and it makes me a bit concerned about IronRuby overall, because that points to inheritance being different in IronRuby than it is in MRI.

There's a case in the IronRuby issue tracker that references the issue, but I didn't particularly like the presented workaround of editing the Sinatra source directly. I would personally much rather monkey patch the code in that case so that upgrades are at least slightly less likely to clobber the fix. The workaround presented in the issue report also bypasses buffering the file output, so using that workaround could cause some issues on larger static assets. I decided instead to wrap up the File object, rather than extend it, and implement the methods that are called by Sinatra on the StaticFile class. Here's my finished patch: