angular/packages/forms/signals/src/util
Alex Rickabaugh 849dba6c65 fix(forms): implement custom control reset propagation
Introduce a highly decoupled FVC and CVA custom control reset mechanism, and implement the framework-wide automatic `transformedValue` and native controls clearing bridge for both new Signal Forms and legacy forms (Template-driven and Reactive).

1. Custom Control Reset Propagation (Bug #2):
- Establish agnostic custom control resetting via `FormFieldBindingOptions.reset` in `FormField`.
- Ensure that `FieldNode.reset()` unconditionally triggers `writeValue` updates on CVA custom controls.
- Protect against duplicate writes during subsequent change detection updates in `control_cva.ts` by verifying and tracking previous written values in the local bindings cache.

2. Unified Framework-wide FormControl Integration:
- Introduce a monorepo-wide private InjectionToken `ɵFORM_CONTROL_INTEGRATION` and `ɵFormControlIntegration` interface to act as the single, decoupled bridge for hooking up FVC parse errors and receiving control resets across both Signal and legacy forms architectures.
- Simplify Signal Forms: make `FormField` implements `ɵFormControlIntegration` directly, removing the intermediate context object and reducing DI boilerplate down to a clean `useExisting: FormField` provider. Triggers the `onReset` callback directly inside `FormField.reset()`.
- Upgrade Legacy Forms: `NG_CONTROL_INTEGRATION_PROVIDER` provides the renamed token. `NgControl` handles the event subscription internally (`set onReset(callback)`) to recursively listen to `control.events` (`FormResetEvent`) lazily only when assigned, resolving all `FormControl` swapping timing and lifecycle cleanup races automatically.

3. Automatic `transformedValue` and Native Controls Utility Clearing:
- Make `Parser.reset()` method required in the interface for a cleaner and non-defensive execution.
- Wire `transformedValue` into the new integration token `ɵFORM_CONTROL_INTEGRATION` to clear validation parsing states on resets.
- Lazily resets the UI-facing `rawValue` linked signal utilizing the original native `linkedSignal.set` callback (`originalSet`), correctly bypassing the UI-to-model parser loopback and preventing redundant model writes during `reset()`.
- Wire up Native Controls (`control_native.ts\Device`): Hook `parent.onReset` inside native element creation to automatically trigger the native `parser.reset()` and force DOM writes (`setNativeControlValue`) back down to the DOM input value during resets, ensuring native elements with pending parsing validation errors are successfully cleared and synced on form resets.

TAG=agy
CONV=8b4cee1e-2117-42a4-b242-c8ec7bf01752
2026-05-06 10:45:40 -07:00
..
array.ts perf(forms): optimize reactivity by using shallow array equality 2026-04-30 15:41:45 -07:00
deep_signal.ts perf(forms): shortcut deepSignal writes if value is unchanged 2026-05-05 09:28:00 -07:00
normalize_form_args.ts refactor(forms): address feedback 2026-03-02 08:46:43 -08:00
parser.ts fix(forms): implement custom control reset propagation 2026-05-06 10:45:40 -07:00
type_guards.ts feat(forms): add experimental signal-based forms (#63408) 2025-08-28 09:02:43 -07:00