What are the downsides to using Spark over Halo in Flex?

Question

Is there more work, or source code files required to customize your look and feel (skins)? How maintainable and readable is Spark relative to Halo? Is it more productive and

Answer 1

Having done quite a bit of skinning with both halo and spark, I can say I find spark to be much more flexible (no pun intended). With halo, I used to spend a lot of time writing ActionScript to draw programmatic skins. Flex 4 introduced the new states model and FXG, which allows you to create your skins with MXML. Less code, more readable, much more maintainable in my experience. The separation of form and function is also much more clean with spark. It took my a good amount of time to really get my head around the spark way of doing things, but in the end it was worth the effort. On the downside, I'm finding the spark control set to be incomplete (no Tree, DataGrid, DividedBox, DatePicker, ColorPicker, icon Button, to name a few), and the new spark controls have their quirks (why doesn't the DropDownList size itself to its content like its halo counterpart?!), but overall I'm happy.