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These past few days, I’ve held a company-specific course on NHibernate. It went really well, and I believe the participants also got those few golden eggs that makes the course worthwhile for them. They had been using NHibernate for some time and have specialists abroad – so, it was with some trepidation I approached the [...]
I am reading up on usability at the moment and I passed a usability guru’s website – Jacob Jensen. He has strong opinions – and I like strong opinions and tend to agree with him mostly. Well, that’s up until now – I read an article by him entitled “Google makes you dumber” (link). That [...]
Sometimes, I’m wondering whether anyone is actually reading my posts here at GoblinCave. I realize that many will stop by only once or twice when a google search has turned this way – but I have no idea if there is an audience for the posts I’m writing. So, a quick raise of hands (read: [...]
I’ve saved the goodies for the last post. We are now ready to edit an order after post 9 – and we want to do it in style. We want to present the user with a really nice interface for fast input. We could have done it the old-fashioned way with an ‘Add’ button for adding an orderline in a new window, but hey, we got a shiny ‘new’ DataGrid in 4.0 – so let’s put that for a spin:
We are now turning towards a somewhat more involved example after a little break in part 8 – the orders. We’ll make a bit more complex filter for the list of orders while keeping it paged – the IOrdersViewModel is so akin to ICustomersViewModel that I’ll jump to the differences in the IOrderFilter:
Okay, we have successfully created a small application in part 7 where the user can add, edit and remove customers. Not bad considering the small amount of code in the solution. Still we have a lot of classes involved and this alone creates a lot of complexity. We are paying the price for a very stable and easy-to-maintain solution down the road. I hope this will be easy to see when we start implementing entity number two – the order.
Okay – part 6 was ViewModels – now it is time for the eye-candy and unleashing the power of the ViewModels. All views (save one) will implement the IView<TViewModel> interface which has a single method: void SetViewModel(TViewModel viewmodel). I’ll explain later why there are no more methods…
Okay – so in post 5 we have managed to get and find data – now we need to be able to perform interactions with the data. We need an implementation of interface ICustomerDetailViewModel:
We introduced commanding in part 4 and so far we have mostly been trying to get to the point where we can actually see something on the screen – and now we will look at the data behind the view. Enter the ViewModel. The responsebility of the ViewModel (in my version, at least) is to act as a mediator between the (dumb) View and the Model.
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