# Form

react-hook-form bindings for accessible form fields: FormField, FormItem, FormLabel, FormControl, FormDescription, and FormMessage with automatic error wiring.

- Category: Forms
- License: MIT
- Page: https://www.saasuji.com/components/form
- Install: npx shadcn@latest add https://www.saasuji.com/r/form.json

## Props

| Prop | Type | Default | Description |
| --- | --- | --- | --- |
| form (Form) | `UseFormReturn<TFieldValues>` | — | Provider props: spread the object returned by useForm() into <Form>. |
| control | `Control<TFieldValues>` | — | react-hook-form control object passed to FormField. |
| name | `FieldPath<TFieldValues>` | — | Path of the field inside the form values. |
| rules | `RegisterOptions<TFieldValues>` | — | Validation rules such as required, min, max, pattern, and validate. |
| render | `(props: { field: ControllerRenderProps; fieldState: ControllerFieldState; formState: FormState }) => React.ReactElement` | — | Render prop receiving the field binding, validation state, and form state. |
| htmlFor (FormLabel) | `string` | — | Overrides the automatically generated id from FormItem. |
| className (FormItem, FormLabel, FormControl, FormDescription, FormMessage) | `string` | — | Additional classes merged onto the sub-component that receives it. |
| children (FormItem, FormLabel, FormControl, FormDescription, FormMessage) | `React.ReactNode` | — | Field label, control, description, and message content. |
| useFormField | `() => { id: string; name: string; formItemId: string; formDescriptionId: string; formMessageId: string } & FieldState` | — | Hook returning the ids and validation state generated for the enclosing FormField. |

## Source

```tsx
"use client"

import * as React from "react"
import type { Label as LabelPrimitive } from "radix-ui"
import { Slot } from "radix-ui"
import {
  Controller,
  FormProvider,
  useFormContext,
  useFormState,
  type ControllerProps,
  type FieldPath,
  type FieldValues,
} from "react-hook-form"

import { cn } from "@/lib/utils"
import { Label } from "@/components/ui/label"

const Form = FormProvider

type FormFieldContextValue<
  TFieldValues extends FieldValues = FieldValues,
  TName extends FieldPath<TFieldValues> = FieldPath<TFieldValues>,
> = {
  name: TName
}

const FormFieldContext = React.createContext<FormFieldContextValue>(
  {} as FormFieldContextValue
)

const FormField = <
  TFieldValues extends FieldValues = FieldValues,
  TName extends FieldPath<TFieldValues> = FieldPath<TFieldValues>,
>({
  ...props
}: ControllerProps<TFieldValues, TName>) => {
  return (
    <FormFieldContext.Provider value={{ name: props.name }}>
      <Controller {...props} />
    </FormFieldContext.Provider>
  )
}

const useFormField = () => {
  const fieldContext = React.useContext(FormFieldContext)
  const itemContext = React.useContext(FormItemContext)
  const { getFieldState } = useFormContext()
  const formState = useFormState({ name: fieldContext.name })
  const fieldState = getFieldState(fieldContext.name, formState)

  if (!fieldContext) {
    throw new Error("useFormField should be used within <FormField>")
  }

  const { id } = itemContext

  return {
    id,
    name: fieldContext.name,
    formItemId: `${id}-form-item`,
    formDescriptionId: `${id}-form-item-description`,
    formMessageId: `${id}-form-item-message`,
    ...fieldState,
  }
}

type FormItemContextValue = {
  id: string
}

const FormItemContext = React.createContext<FormItemContextValue>(
  {} as FormItemContextValue
)

function FormItem({ className, ...props }: React.ComponentProps<"div">) {
  const id = React.useId()

  return (
    <FormItemContext.Provider value={{ id }}>
      <div
        data-slot="form-item"
        className={cn("grid gap-2", className)}
        {...props}
      />
    </FormItemContext.Provider>
  )
}

function FormLabel({
  className,
  ...props
}: React.ComponentProps<typeof LabelPrimitive.Root>) {
  const { error, formItemId } = useFormField()

  return (
    <Label
      data-slot="form-label"
      data-error={!!error}
      className={cn("data-[error=true]:text-destructive", className)}
      htmlFor={formItemId}
      {...props}
    />
  )
}

function FormControl({ ...props }: React.ComponentProps<typeof Slot.Root>) {
  const { error, formItemId, formDescriptionId, formMessageId } = useFormField()

  return (
    <Slot.Root
      data-slot="form-control"
      id={formItemId}
      aria-describedby={
        !error
          ? `${formDescriptionId}`
          : `${formDescriptionId} ${formMessageId}`
      }
      aria-invalid={!!error}
      {...props}
    />
  )
}

function FormDescription({ className, ...props }: React.ComponentProps<"p">) {
  const { formDescriptionId } = useFormField()

  return (
    <p
      data-slot="form-description"
      id={formDescriptionId}
      className={cn("text-sm text-muted-foreground", className)}
      {...props}
    />
  )
}

function FormMessage({ className, ...props }: React.ComponentProps<"p">) {
  const { error, formMessageId } = useFormField()
  const body = error ? String(error?.message ?? "") : props.children

  if (!body) {
    return null
  }

  return (
    <p
      data-slot="form-message"
      id={formMessageId}
      className={cn("text-sm text-destructive", className)}
      {...props}
    >
      {body}
    </p>
  )
}

export {
  useFormField,
  Form,
  FormItem,
  FormLabel,
  FormControl,
  FormDescription,
  FormMessage,
  FormField,
}

```