Has somebody already evaluated the new MS Silverlight RAD tool "Lightswitch"? Is it also suitable for developing complex applications? Can I use it without Silverlight knowledge? Is it so flexible, that I can also extend "Lightswitch appications" with own code (C#,XAML)?
Based on the videos it is certainly powerful for developing data-centric business applications (i.e. the majority of business application).
Re Silverlight: Only .Net knowledge is assumed for the basics, but it is always wise to have platform specific knowledge of a technology you want to deploy on.
Like any code gen tool, it will do simple stuff easily and anything not provided in-the-box will require more effort, however I feel they made a very smart move generating standard C# (or VB) .Net projects you can extend using knowledge you [likely] already have.
As the same type of business code has been written manually countless times I think this has a lot of potential for eliminating drudge coding work. We will certainly keep an eye on it and evaluate it in detail (especially with a view to cheaply replacing legacy apps).
It assumes that all “data rows” can be edited in isolation and therefore checks that a “row” is valid before letting the user “OK” the editor form.
In most cases this is not a problem, however if you have an application domain when the user need to edit “many” objects before the system becomes valid again, then Lightswich is unlikely to be a good option for you.