58 lines
2.0 KiB
Dart
58 lines
2.0 KiB
Dart
import 'package:flutter/widgets.dart';
|
|
|
|
/// Mixin for stateful screens that wrap their async work in a busy + error
|
|
/// scaffolding. Exposes [busy] and [errorText] state plus a [runAsync] helper
|
|
/// that clears the prior error, sets busy, runs the body, captures any
|
|
/// exception via an optional [errorMapper], and clears busy in `finally` —
|
|
/// all mounted-guarded.
|
|
///
|
|
/// Mid-flow state changes (e.g. clearing busy *before* the body finishes so
|
|
/// the UI can swap into a "waiting" panel) are still possible via [setBusy]
|
|
/// from inside the [runAsync] body — the `finally` clears busy idempotently.
|
|
mixin AsyncFormStateMixin<T extends StatefulWidget> on State<T> {
|
|
bool _busy = false;
|
|
String? _errorText;
|
|
|
|
bool get busy => _busy;
|
|
String? get errorText => _errorText;
|
|
|
|
/// Set busy without forcing a setState when the value didn't change.
|
|
void setBusy(bool value) {
|
|
if (!mounted || _busy == value) return;
|
|
setState(() => _busy = value);
|
|
}
|
|
|
|
/// Set the error text directly (e.g. for synchronous validation failures
|
|
/// or post-success rejections like a duplicate-account guard).
|
|
void setErrorText(String? value) {
|
|
if (!mounted || _errorText == value) return;
|
|
setState(() => _errorText = value);
|
|
}
|
|
|
|
/// Run [body] surrounded by busy/error scaffolding. Returns the body's
|
|
/// value, or `null` if the widget unmounted, the body threw, or the
|
|
/// errorMapper translated the exception.
|
|
Future<R?> runAsync<R>(
|
|
Future<R> Function() body, {
|
|
String Function(Object error)? errorMapper,
|
|
bool Function()? shouldApplyState,
|
|
}) async {
|
|
bool canApplyState() => mounted && (shouldApplyState?.call() ?? true);
|
|
if (!canApplyState()) return null;
|
|
setState(() {
|
|
_busy = true;
|
|
_errorText = null;
|
|
});
|
|
try {
|
|
return await body();
|
|
} catch (e) {
|
|
if (canApplyState()) {
|
|
setState(() => _errorText = errorMapper?.call(e) ?? e.toString());
|
|
}
|
|
return null;
|
|
} finally {
|
|
if (canApplyState()) setState(() => _busy = false);
|
|
}
|
|
}
|
|
}
|