on AIR Bus Tour Boston: Taking apart the bus
Mike Chambers gave a talk about some of the technology being used on the tour bus. Using AIR applications to help track the location, what is going on, and display the information on the web.
Code for all the applications is available from Google code.
AIRTracker: Application that gets GPS info periodically and posts it to the server. The AIR application is passed the GPS coordinates via command line arguments. Uses a program called GPSBabel to get the GPS information. Command line arguments are handled through an invoke event.
Shell.shell.addEventListener(InvokeEvent.EVENT, handler);
If your application is already running, the handler will get called again with the new arguments. The application queues up GPS point data to handle server up/down and connection online/offline. Stores them in a local file using binary serialization of the AS3 array. It waits for ACK from server before removing data from the array. In order to serialize the custom class in the array you need to add metadata to the class.
[RemoteClass(alias="com.adobe.onair.geo.GeoPoint")]
He pointed out that there is no compile time checking so you could type the class name wrong. Showed an example using SocketMonitor to do a low level check for connectivity. The application demonstrates a common pattern of queuing and saving data locally and pushing the data up to server as connectivity is available. Handles both connectivity issues and application crashes. Shows a good robust application. Application and server interaction is easy since there is a single source of data which removes the need to handle conflict resolution.
He next showed pictures of the hardware on the bus. The hardware for grabbing the GPS coordinates was a Garmin GPS 18, which is a hockey puck sized device that attaches to the top of your vehicle.
AIRSnapshot: Application that every minute takes a picture (JPG format), geo encodes it, and uploads it to Flickr with appropriate tags. Application shows handling bigger data and multiple queues. It has to go to the server twice, first to upload the picture and a second time to add the geo tags.
flump: Application that downloads all of your raw Flickr images. Used this to pull all of the pictures from the bus and put them together into a movie available on The Flex Blog.
Audience asked about using AIR to broadcast a live video stream, which sounded like it was possible.