Real Time? How About Node.js...We wanted a tool that would allow us to monitor snapshots as they occur in real time by listening to our snapshots directory and pushing newly added photos to a web client. At first, Node.js seemed like the perfect tool for the job. In fact, with a combination of Node.js, Express, Socket.IO and a directory watcher module, we had a simple implementation up and running on my local machine in little time. Unfortunately, we soon discovered that, while it worked well for watching directories on my local machine, the Node.js event based file watcher does not work with network drives. As a result, we turned back to our good friend Ruby.
Back to Ruby...Not only would we be able to watch the network drive with Ruby, it has the added benefit of being the lingua franca of our testing team. This means that all members of the testing team can feel more comfortable reading and contributing to the project's code base in the future. The application was built using Ruby, Sinatra, and a directory watcher gem, making the server side code simple enough to place in a single server.rb file:
On the client side, we long poll the server for new events, passing in the time stamp of our latest result. As you can see, the server then hands over all events with a time stamp later than the one we passed in. The client takes that response and adds each event to the page. Now, we are able to visit the "Quality Center Snapshot Feed" web page and watch the fail pics roll in.