CODEWITHSUNDEEP
c#wpfsilverlightmvvm
Iceman
Iceman

Reputation: 80

MVVM without commands

I'm learning Silverlight/MVVM. Now I'm facing problem with Commands, that I think are just overcomplicated. I wanted to execute close on child window after command.
According to separation of concers it should be execute from view, as I understand.
As far as I looked for solution I found it and it wasn't trivial for such a trivial task.

To sum it up, I must say that separation of view, viewmodel and model are great ideas.
Also Binding from View to ViewModel is nice and clean. But what about Commands. As I understand they are just piece of code to execute (like delegates).But they are too complicated and troublesome.

I want to know you opinion. What about idea that VieModel would have properties and normal public methods, that it will be executed from events of views. If I will not pass any view related element to the view model it still will be MVVM, right?

Of course, there will be one drawback, that i will have to bind separatly IsEnabled to properties in ViewModel to mimic CanUpdate functionality of Commands. It's not that you view doesn't know about ViewModel. Views are not very testable, are they?

It would be very flexible. For example, in event for click i would do some strict view logic, call method from viewmodel object and then maybe call another method and after all that do some more view logic.

So, what do you think?

Upvotes: 0

Views: 292

Answers (1)

alex
alex

Reputation: 12654

You can try using Cailburn.Micro. It is an open-source framework that runs over WPF and hides some of it complexities. For example, it replaces command-classes with just plain method calls.

You can implement windows-closing by returning a special result that will do the actual closing of the view. That way your ViewModel will still be fully unit-testable, as you can check that expected result is returned, and it will not be view-aware.

Here is an example on how to implement this: https://stackoverflow.com/a/10175228/258737

Upvotes: 2

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