CollectionView
CollectionView is a very interesting construct. After including it in my ViewModel I meant to quickly blog about the usage...but when I started thinking about it and reading a bit more about it, it becomes even more interesting. Lots of good blogging. However, while I think about it, let me quickly make my original point.
The Model has a simple List. CollectionView wraps a Collection and adds concepts like selection, sorting and filtering to it and supports the INotify... goodness that data binding wants in order to do a really good job. So, CollectionView is a construct that wraps a Model class and adapts it for data binding from the UI. Uh...sounds like a ViewModel!
WPF does not use the terminology of M-V-VM, but it repeatedly uses the pattern. CollectionView is a fine class name, but in very strict terms it isn't part of the View! A CollectionView implies it has UI.
If you really want to understand the M-V-VM pattern, there is no better place to start than to study how CollectionView adapts a Collection to be presented in the UI using data binding.
Going to visit the in-laws, so blogging will be sporatic for awhile.
- Anonymous
March 07, 2006
John,
This mirrors the concepts in System.Data of DataTable and DataView, where a DataView adds sorting and filtering on top of DataTable.
It's almost like a mini MVC model within the viewmodel - in there, you've got the DataTable (the Model), then you can have N DataViews "showing" different selections/sorts/etc on the underlying Table. Update the table once, and all bound DataViews update accordingly. Hence, DataView.
Sounds like CollectionView is analagous. - Anonymous
March 11, 2006
I am not familiar with CollectionView ... do you have any links that would point the un-initiatied in the right direction? - Anonymous
March 13, 2006
John Gossman has posted the first part of his long-awaited example of a Model-View-ModelView architecture,...