Move from IReactiveDerivedList to DynamicData

Question

Has simple code in old version of ReactiveUI:

var allItems = new ObservableCollection<Model>(items);
var filteredItems = allItems.CreateDerivedCollection(
 x => x,
 Filter,
 Comparer.Compare);

where Filter and Compare has simple signatures:

private bool Filter(Model item)
public int Compare(Model x, Model y)

sometimes i change items in other threads (big changes, without INPC) or change Filter\Compare strategies and just do filteredItems.Reset();

---

In DynamicData i try to:

          ReadOnlyObservableCollection<Model> filteredItems;
          var allItems = new ObservableCollection<Model>(items);
          var cancellation = allItems
            .ToObservableChangeSet()
            .Filter(Filter)
            .Sort(Comparer)
            .ObserveOn(SynchronizationContext.Current)
            .Bind(out filteredItems)
            .DisposeMany()
            .Subscribe();

but not found, how to Reset this^ or filteredItems.

Answer 1

Wish I were able to give you a direct answer, but I'm rather new to ReactiveUI. Managed to use DynamicData for something and thought you wouldn't mind this sharing.

If what I say later doesn't help you, here are the most relevant resources I could find:

• https://floatingcube.com/blog/convert-reactive-list-to-dynamic-data/
• https://github.com/reactiveui/DynamicData/wiki/Introduction-for-ReactiveUI-users
• https://github.com/reactiveui/DynamicData/issues/182
• https://habr.com/en/post/454074/

---

In my case I used SourceList or SourceCache as type for something similar to your allItems.

SourceCache<Model, string> allItems =
    new SourceCache<Model, string>(m => m.Id);

// assuming each model has unique id; if it doesn't then use SourceList

I'd then have a BindingList<Model> as type for something simlar to your 'filteredItems'.

BindingList<Model> filteredItems = new BindingList<Model>();

The binding should be something like:

allItems
    .Connect()
    ...
    .ObserveOn(...)
    .Bind(filteredItems)
    .Subscribe();

To bulk-edit the list I'd call something like

allItems.Edit(
    innerList => {
    innerList.Clear();

    // edit
    // innerList.AddOrUpdate(...);
});

---

Cheers !