Cancel superseded async page loads to fix stale-load race#100
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Page ViewModels started their data loads as fire-and-forget async work with no cancellation (HomeViewModel.Initialize and ItemDetailsViewModel.HandleParameters were async void; LibraryViewModel fired `_ = InitializeAsync()` and `_ = RefreshItemsAsync()` from every sort/filter change). A superseded load's post-await continuation could overwrite newer view-model state - for example, rapidly toggling library filters could leave the grid showing the results of an earlier selection. Introduce a small shared CancellableLoad helper that owns a CancellationTokenSource, cancels any prior in-flight load when a new one starts, and swallows the superseded OperationCanceledException. Each affected ViewModel routes its load entry points through it and threads the cancellation token into every Kiota GetAsync call, so a superseded request is cancelled at the HTTP layer. Terminal state commits are guarded with ThrowIfCancellationRequested so an already-completed request cannot write stale state, and IsLoading is only cleared by the surviving load.
CyberoniOntoni
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Jun 23, 2026
Rebased onto main with conflict resolution against dfederm#93 (controller shell), dfederm#97 (packaging), and dfederm#100 (CancellableLoad). - Add shell search bar, Search page, and ShellFocusCoordinator - Fix library filter XY-focus in code-behind; up-from-home focuses search - Route collection folders via CollectionNavigation; async item lookup for search - Keep CancellableLoad for ItemDetails/SearchViewModel; add CancelAsync for navigate-away - ItemDetails null-safety and ResetDisplayState on reload
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What & why
Page ViewModels started their data loads as fire-and-forget async work with no
cancellation, so a superseded load's post-await continuation could overwrite newer
view-model state. The most reproducible case: rapidly changing a library's sort or
filters could leave the grid showing the results of an earlier selection.
This introduces a small shared
CancellableLoadhelper that owns aCancellationTokenSource, cancels any prior in-flight load when a new one starts, andswallows the superseded
OperationCanceledException.HomeViewModel,LibraryViewModel(including every sort/filter refresh path), and
ItemDetailsViewModelroute their loadentry points through it and thread the cancellation token into each Kiota
GetAsynccall,so a superseded request is cancelled at the HTTP layer. Terminal state commits are guarded
with
ThrowIfCancellationRequestedso an already-completed request can't write stale state,and
IsLoadingis only cleared by the surviving load.Type of change
Checklist
together unrelated changes.
msbuild JellyBox.sln -t:Build -p:Configuration=Debug -p:Platform=x64succeeds with 0 warnings and 0 errors.
data-loading correctness fix with no visual or layout change.
Manual test notes
Windows desktop — rapidly toggled a library's sort direction, sort option, and filters in
quick succession. The grid consistently settles on the final selection's results, and the
loading indicator clears correctly.
Screenshots / recording
N/A — no visual or layout change; this is a data-loading correctness fix.
Out of scope / follow-ups
None.