I was working on a scrum team that wanted to make our burn down charts available on our wiki. We tried the movable type chart plugins and they worked ok but we lacked the control we needed. I had heard about google charts and after looking into them I realized that we might be able to coax these to produce the charts we were missing. To my surprise this was quite easy to prototype but a little harder to do in practice. The nice thing about the google charts, is they are essentially image tags with specifically built URL’s. Constructing the URL can be a challenge but in general the performance we observed was great and the price (free) can’t be beat. You can read more about it here.

Before I get into how this could be used, take a look at some examples in this sample gallery.

Ok, how does this help?

First thing to note is the above samples are all generated on the fly using the google chart api. If you look at the image url’s you’ll see that all of the chart parameters/colors/data/format etc… are provided on the url line to google. This is simple but you obviously don’t want to do this by hand. This is where you can get creative. Say you have a web based data source (say one that stores project story points by sprint), you could coax that web service to produce json or xml data to your static page which could run some embedded javascript to produce a url to the Google charts API. Not totally trivial but since there are no server side elements (other than your feed), you can do this with minimal infrastructure.

I experimented with a simple rails app that allowed us to record the story point progress and plans on a few sprints. One of the side effects is it could produce nice looking burn down charts by generating the necessary url to feed to google charts. I’ll try to post more about this later with some examples (sanitized).