Binding/update issue with ReactiveElmishViewModel

[TeaDrivenDev]

Using setters of ReactiveUI-style notifying properties in a class deriving from ReactiveElmishViewModel does not cause UI updates.

member this.Progress
    with get () = progress
    and set value =
        this.RaiseAndSetIfChanged(&progress, value) |> ignore

Changing the class to inherit from ReactiveObject instead makes the updates work as expected; thus my suspicion is that this may have do with the fact hat ReactiveElmishViewModel implements INPC by itself, rather than using the existing implementation in the ReactiveObject base class.

Code demonstrating the issue is at https://github.com/TeaDrivenDev/Shoo/blob/ReactiveElmishViewModel_BindingIssue/src/Shoo/ViewModels/MainWindowViewModel.fs

[JordanMarr]

You are correct. I did that’s as a workaround in order to implement OnPropertyChanged, even though I knew it was a bit of a hack, but was just trying to get it done.

[JordanMarr]

That turned out to be an easy fix. Don't know how I missed that the first time through.

v1.0.2 should fix this so it uses ReactiveObject INPC instead.

[JordanMarr]

It looks like you are fully embracing ReactiveUI, which is nice to have the option.

I did update the BindSourceCache method to have two optional map and sortBy arguments. I wonder if that would work for your solution?

See the Todos in the sample project:

type TodoListViewModel() =
    inherit ReactiveElmishViewModel()

    let store = 
        Program.mkAvaloniaProgram init update
        |> Program.mkStore

    member this.Todos = 
        this.BindSourceCache(
            store.Model.Todos
            , map = fun todo -> TodoViewModel(store, todo)
            , sortBy = fun todo -> todo.Completed, todo.Description
        )
    member this.AddTodo() = store.Dispatch AddTodo
    member this.Clear() = store.Dispatch Clear

    static member DesignVM = new TodoListViewModel()

[TeaDrivenDev]

I haven't used those here because I need access to the intermediary IObservable<IChangeSet<_, _>> to also feed the move queue. I think I know a way to do both; I'll have to have a look tomorrow at how I like that.

[TeaDrivenDev]

I did update the BindSourceCache method to have two optional map and sortBy arguments. I wonder if that would work for your solution?

Turns out they're too high level in this case, as the map uses .Transform(), but I need .TransformWithInlineUpdate(). So what I'd need I suppose is a more general transformation IObservable<IChangeSet<'TValue, 'TKey>> -> IObservable<IChangeSet<'TTransformedValue, 'TKey>> that plugs in between the .Connect() and .Bind() (or .Sort()) and gives more control over the process.

[JordanMarr]

Btw, did v1.0.2 resolve your issue with regards to the INotifyPropertyChanged implementation?

[TeaDrivenDev]

It did, thanks!

Closing this; I'll open a discussion about support for more advanced DynamicData/Rx sometime.