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Error Boundary

Catches panics during build, layout, paint, and hit-testing, displaying fallback UI instead of crashing the app.

Basic Usage​

widgets.ErrorBoundary{
    Child: riskyWidget,
    FallbackBuilder: func(err *drifterrors.BoundaryError) core.Widget {
        return widgets.Text{Content: "Something went wrong"}
    },
    OnError: func(err *drifterrors.BoundaryError) {
        log.Printf("Widget error: %v", err)
    },
}

Properties​

PropertyTypeDescription
Childcore.WidgetThe widget tree to protect
FallbackBuilderfunc(*BoundaryError) WidgetBuilds fallback UI when an error is caught
OnErrorfunc(*BoundaryError)Called when an error is caught

Error Widgets​

WidgetPurpose
ErrorWidgetInline error display (default fallback)
DebugErrorScreenFull-screen error with stack trace (debug mode)

Programmatic Control​

Access the boundary's state from descendant widgets:

state := widgets.ErrorBoundaryOf(ctx)
if state != nil && state.HasError() {
    state.Reset()  // Clear error and retry rendering
}

Common Patterns​

Scoped Error Handling​

Wrap specific subtrees to isolate failures:

widgets.Column{
    Children: []core.Widget{
        HeaderWidget{},  // Keeps working
        widgets.ErrorBoundary{
            Child: RiskyWidget{},
            FallbackBuilder: func(err *drifterrors.BoundaryError) core.Widget {
                return widgets.Text{Content: "Failed to load"}
            },
        },
        FooterWidget{},  // Keeps working
    },
}

Global Error Handling​

Wrap the entire app for production:

func main() {
    drift.NewApp(widgets.ErrorBoundary{
        Child: MyApp{},
        FallbackBuilder: func(err *drifterrors.BoundaryError) core.Widget {
            return MyCustomErrorScreen{Error: err}
        },
    }).Run()
}