Overview

Flutter form validation and state management without a framework on top. advanced_forms gives you typed field controllers, composable sync and async validation, and form-level state tracking, built on ChangeNotifier and ValueListenable.

• Typed field controllers — text fields, checkboxes and switches, dropdowns and radio groups, and multi-select fields, each with its own value type and its own error type.
• Validators that compose — filled, notEmpty, notNull, atLeastLength, notLongerThan, exactly and numeric checks, combined with & and |, or any E? Function(T) you write yourself.
• Async validation — debounced server-side checks ("is this email taken?") with a timeout, failure handling and cached answers.
• Cross-field validation — re-run a validator when the fields it depends on change, or derive one field's value from another.
• Validation modes — validate on submit, on every keystroke, or on unfocus. Set once, applied to the whole form.
• Subforms — attach and detach nested form controllers; their fields join the parent's validate, reset, read-only and error handling.
• Form-level state — canSubmit, wasModified, validating and validationErrors, ready to bind to a submit button.
• Read-only fields and server-side errors — freeze a value, or push an error in from an API response.
• Granular rebuilds — one builder per field, so a keystroke rebuilds one subtree and nothing else.

General overview

Where to next

Also see the example app — a runnable gallery where every pattern in these docs has a working screen.

Maintained by LeanCode.