I have a typical master-detail scenario. User can click "Add New" in the master view and enter the details in the detail view. So for example lets say I have list of ObservableCollection of Product. When the user clicks "Add New", I add a new Product record to the ObservableCollection and then open a detail view for adding the Product details. This works well if the user does save the product. However if the user decides to cancel the addition of new Product, how do I remove the same from the ObservableCollection of Product in the master view. Right now I could think of two ways, first to pass the reference of ObservableCollection to the Details view, and second, use events to notify master view about the new Product record deletion. What do you suggest ? Also, if there is better way to handle this in prism specifically, please let me know.
regards, Nirvan.
Passing a reference to the ObservableCollection to the details view is a no-no - it should only know about the record it is bound to.
You have not specified the UI you have in place for this, there can be a couple of ways to do this that may be better suited for your design. However one reasonably agnostic way to do it is to use the EventAggregator to publish the event which the master view can subscribe to. It is up to the master view how to deal with that event, different views can respond in different ways. In this particular case the master view can check the currently selected item, and if it is new (i.e. hasn't been saved, doesn't have key pieces of info like an ID) then it can simply remove it from the collection and discard it.