May 14th, 2007
I decided it was about time that I learnt how to use Flex. The best way to learn is always by building something so I decided that I’d build a little app to connect to the Slim Timer API and make it easy to keep track of your time. It seemed like something that was perfectly suited to Flex – built from UI components and connecting to an XML webservice.
So here it is: Slimmer Timer. You can download Mac and PC versions as well as seeing a screenshow on the project page at that link.
Although building the app was relatively straightforward, there are some gotchas that I ran into which I thought I would expand on a little here… All of these issues are as I experienced them in the standalone debug player – they may happen differently in the browser plugin.
- Setting contentType and a custom “Accept” header on a HTTPService only works when the method is POST. If you change the method to GET then these extra headers aren’t sent along with the request.
- The HTTPService.method documentation is very misleading… GET and POST are the only valid values unless you are using FDS as a proxy. More info on that on this post on FlexCoders
The solution to these problems was to wrap my generated swf in a Screenweaver Hx program. This makes it easy to write a little bit of haXe code which can intercept network calls from the flash and act on them. The haXe wrapper adds the required HTTP headers to my GET calls and also allows Flash to make PUT requests.
To support HTTP PUT requests I appended a “put=true” onto the URL requested by Flash which the haXe wrapper detects and then changes the HTTP request type. haXe’s HTTP class doesn’t support methods other than GET and POST but because it is open source I could easily extend this class to suit my needs. The haXe files I wrote can be seen here if you are interested…
As well allowing me to tweak the network behaviour and therefore make my app work, Screenweaver allowed me to remove the chrome from the app window and make the app slightly transparent. These extras help it to live up to it’s name of “Slimmer Timer” :)
As SlimmerTimer was my first foray into the world of Flex it’s not as well coded as it could be. I’m currently rewriting it using the Cairngorm framework so there may be a better version out some time soon but for now I think it’s quite useful as what it is – a simple little app for keeping track of your time.