Is it a trend to use presentation layer to control the business logic?
The answer is NO. This is because:
- Even if this is a trend, this is then just one of the two trends (viewing from a particular perspective). One trend is called thin client, and the other is called thick client. The trend you talked about is thick client, which means the client side does lots of work (too much ?-). Now this makes your client more like a desktop application, and tend to enjoy less benefits provided by the web-based application architecture.
- From a high level design view, business logic is an entity clearly seperated from your presentation layer. 99% of the time, your business logic for each single procedure, could potentially involve many clients (other than that 1% of those most simple business logic). To tightly bundle them with presentation layer makes no sense. I view it as a failure to mix up major components of your application, and believe that it would seriously damage the potential growth of your application. Going the wrong way is fatal ;-)