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POBi-directional view model syncing with "live" collections and properties
 

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    <p>I am getting my knickers in a twist recently about View Models (VM).</p> <p>Just like <a href="https://stackoverflow.com/questions/1256793/mvvm-sync-collections">this guy</a> I have come to the conclusion that the collections I need to expose on my VM typically contain a different type to the collections exposed on my business objects.</p> <p>Hence there must be a bi-directional mapping or transformation between these two types. (Just to complicate things, on my project this data is "Live" such that as soon as you change a property it gets transmitted to other computers)</p> <p>I can just about cope with that concept, using a framework like <a href="http://truss.codeplex.com" rel="nofollow noreferrer">Truss</a>, although I suspect there will be a nasty surprise somewhere within.</p> <p>Not only must objects be transformed but a synchronization between these two collections is required. (Just to complicate things I can think of cases where the VM collection might be a subset or union of business object collections, not simply a 1:1 synchronization).</p> <p>I can see how to do a one-way "live" sync, using a replicating ObservableCollection or something like CLINQ.</p> <p>The problem then becomes: What is the best way to create/delete items?</p> <p>Bi-directinal sync does not seem to be on the cards - I have found no such examples, and the only class that supports anything remotely like that is the ListCollectionView. Would bi-directional sync even be a sensible way to add back into the business object collection?</p> <p>All the samples I have seen never seem to tackle anything this "complex".</p> <p>So my question is: How do you solve this? Is there some technique to update the model collections from the VM? What is the best general approach to this?</p>
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    1. COCould you give a short example which collections occur where? I think I understand your problem sort-of, but not completely. What about using the business logic collections but use a converter when using them? What about using a Collection of proxy objects that contain the business logic objects?
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