TanStack Form

TanStack Form with Base UI Field for accessible, type-safe forms. The useAppForm hook (from @/components/form) provides pre-configured form and field components integrated with shadcn's Button and Label.

Conventions

• Always use useAppForm — never raw TanStack Form hooks
• Validate with Zod schemas via validators.onSubmit
• Use field.Control with render prop to bind UI components
• Every field needs field.Root, field.Label, field.Control, and field.ErrorMessage

import { z } from "zod";
import { useAppForm } from "@/components/form";

Form API

Component	Use
form.Root	Wrapper — provides form context, handles submit
form.AppField	Creates a field with access to field sub-components
form.Submit	Submit button — auto-disables when pristine/invalid/submitting
form.Subscribe	Subscribe to form state for custom rendering

Field API

All components available inside form.AppField render callback:

Component	Use
field.Root	Wraps field, connects aria-invalid and aria-describedby
field.Label	Label — auto-connects to input via for/id
field.Control	Input wrapper — handles value/onChange binding
field.ErrorMessage	Shows validation errors

Polymorphic Fields

render prop customizes the underlying element while keeping form state binding:

<field.Root render={<InputGroup.Root />}>
  <field.Control render={<InputGroup.Input placeholder="Email" />} />
</field.Root>

Programmatic Control

API	Use
form.reset()	Reset to default values
form.setFieldValue("name", value)	Set field value
form.state.values	Get current values
form.validate()	Trigger validation

Accessibility

Base UI Field automatically handles — no manual wiring needed:

• aria-invalid on invalid fields
• aria-describedby linking inputs to error messages
• for/id linking labels to inputs
• Disabled state during submission

Examples

See examples/ for complete form examples by pattern:

Example	When to use
examples/basic-form.md	Simple form with validation and submission
examples/polymorphic-fields.md	Custom UI components with render prop

Acceptance Checklist

• Uses useAppForm from @/components/form
• Validates with Zod schema via validators.onSubmit
• Every field has Root, Label, Control, ErrorMessage
• Uses form.Root as wrapper, form.Submit for submit button
• Polymorphic fields use render prop, not manual binding