'use client';

import * as React from 'react';
import { cn } from '@/lib/utils';
import { Label } from '@/components/ui/label';
import { Slot } from '@radix-ui/react-slot';
import { Label as LabelPrimitive } from 'radix-ui';
import { Controller, ControllerProps, FieldPath, FieldValues, FormProvider, useFormContext } from 'react-hook-form';

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, formState } = useFormContext();

  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.HTMLAttributes<HTMLDivElement>) {
  const id = React.useId();
  const { error } = useFormField();

  return (
    <FormItemContext.Provider value={{ id }}>
      <div data-slot="form-item" className={cn('flex flex-col gap-2.5', className)} data-invalid={!!error} {...props} />
    </FormItemContext.Provider>
  );
}

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

  return (
    <Label
      data-slot="form-label"
      className={cn('font-medium text-foreground', className)}
      htmlFor={formItemId}
      {...props}
    />
  );
}

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

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

function FormDescription({ className, ...props }: React.HTMLAttributes<HTMLParagraphElement>) {
  const { formDescriptionId, error } = useFormField();

  if (error) {
    return null; // Hide the description when there's an error
  }

  return (
    <div
      data-slot="form-description"
      id={formDescriptionId}
      className={cn('text-xs text-muted-foreground -mt-0.5', className)}
      {...props}
    />
  );
}

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

  if (!body) {
    return null;
  }

  return (
    <div
      data-slot="form-message"
      id={formMessageId}
      className={cn('-mt-0.5 text-xs font-normal text-destructive', className)}
      {...props}
    >
      {body}
    </div>
  );
}

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

Installation

Examples

Credits

Form

Installation

Examples

Credits
