Avalonia: Binding DynamicData observables enhancement

[aguahombre]

At the moment we can bind a control property to IObservable<T> using the ^ operator.

It would be nice enhancement to be able to bind ItemsControl.Items (etc) to DynamicData observables such asIObservableList<T> and IObservable<IChangeSet<T>> using the same operator.

class MyViewModel
{
   public  IObservableList<MyItem> MyItems { get ;}
}

<ItemsControl Items="{Binding MyItems^}"/>

One benefit would be that the ViewModel doesn't need to create and maintain a ReadOnlyObservableCollection<T> when the view binds directly to IObservableList<T>; the collection will never be created if the View never instantiates the control.

[Gillibald]

IObservableList requires a dependency on DynamicData. Unless we use DynamicData in the core of Avalonia support for this is unlikely to happen.

[aguahombre]

I think you already have an indirect dependency on it as ReactiveUI v10.3.6 depends on DynamicData v6.13.9

[Gillibald]

Avalonia works perfectly fine without ReactiveUI and has no direct dependency as you stated. The binding system is part of the core of Avalonia. This feature should be optional.

[aguahombre]

My mistake, it's only used in the Avalonia.ReactiveUI.
Perhaps someday a DynamicData Binding markup extension could be added to that assembly.

[Gillibald]

I think we need a prototype that uses DynamicData in a sortable, groupable "ItemsControl". The control itself would need direct access to IObservableList etc

[jp2masa]

It should be possible to extend the binding system with a stream plugin:

For reference:

• IStreamPlugin
• ObservableStreamPlugin (implementation for IObservable)
• The list of stream plugin handlers (you can add custom plugins to this list)