Form Management (validasi_ui) experimental

validasi_ui provides headless form management for Flutter, built on top of Validasi. It brings a React Hook Form–style controller + builder pattern, using signals for fine-grained reactivity.

validasi is re-exported from this package, so you do not need to add it as a separate dependency.

Setup

flutter pub add validasi_ui

With code generation:

flutter pub add validasi_ui validasi_annotation
flutter pub add dev:build_runner dev:validasi_gen

Architecture

┌─────────────────────────────────────┐
│ ValidasiForm<T>                     │  InheritedWidget scope
│   ├── schema: ValidasiSchema<T>     │  ← allocates model from controller
│   ├── mode: onSubmit / onBlur / onChange
│   └── controller: ValidasiFormController<T>   (auto-created)
│         │
│         ├── signals (dirty, touched, errors)
│         ├── values (per-field, typed)
│         └── validation (sync + async)
│
└── children ──────────────────────────┘
      │
      ├── ValidasiTextField<T, String>    (text input convenience)
      │     └── builder: (ctx, state, TextEditingController) => Widget
      │
      ├── ValidasiFormField<T, int>       (generic field binding)
      │     └── builder: (ctx, state) => Widget
      │
      └── ValidasiWatch.field<T, V>       (reactive value display)
            └── builder: (ctx, value) => Widget

Key types

Type	Role
ValidasiForm<T>	Root widget — creates + scopes a ValidasiFormController<T>
ValidasiFormController<T>	State manager — values, errors, dirty/touched, validate, submit
ValidasiFormField<T, V>	Binds a ValidasiField<T, V> to a builder; reactive
ValidasiTextField<T, V>	ValidasiFormField + auto TextEditingController lifecycle
ValidasiFieldState<V>	Typed value + errors passed to builder
ValidasiTextController	TextEditingController subclass for text field sync

Two usage patterns

1. With Codegen (recommended) — annotate your model with @ValidateClass, run build_runner, use generated XFields and schema.

2. Without Codegen — define FieldDescriptor and ValidasiField manually. No annotations, no build_runner.