All form reset to default if any field is invalid in 'Chapter 7 - Improving Accessibility.'

[EdoanR]

I'm not sure if it was intended that way, but I can see it being annoying in a longer form. Is there a way to fix this? It would be perfect for me if only the incorrect field ( or none at all ) reverted to default.

https://github.com/user-attachments/assets/3eb93aa0-1739-4036-a42a-def28dd4e717

Here's the form code ( create-form.tsx ):

'use client';

import { CustomerField } from '@/app/lib/definitions';
import Link from 'next/link';
import {
  CheckIcon,
  ClockIcon,
  CurrencyDollarIcon,
  UserCircleIcon,
} from '@heroicons/react/24/outline';
import { Button } from '@/app/ui/button';
import { createInvoice, State } from '@/app/lib/actions';
import { useActionState } from 'react';

export default function Form({ customers }: { customers: CustomerField[] }) {
  const initialState: State = { message: null, errors: {} };
  const [state, formAction, pending] = useActionState(
    createInvoice,
    initialState,
  );

  return (
    <form action={formAction}>
      <div className="rounded-md bg-gray-50 p-4 md:p-6">
        {/* Customer Name */}
        <div className="mb-4">
          <label htmlFor="customer" className="mb-2 block text-sm font-medium">
            Choose customer
          </label>
          <div className="relative">
            <select
              id="customer"
              name="customerId"
              className="peer block w-full cursor-pointer rounded-md border border-gray-200 py-2 pl-10 text-sm outline-2 placeholder:text-gray-500"
              defaultValue=""
              aria-describedby="costumer-error"
            >
              <option value="" disabled>
                Select a customer
              </option>
              {customers.map((customer) => (
                <option key={customer.id} value={customer.id}>
                  {customer.name}
                </option>
              ))}
            </select>
            <UserCircleIcon className="pointer-events-none absolute left-3 top-1/2 h-[18px] w-[18px] -translate-y-1/2 text-gray-500" />
          </div>
          <div id="customer-error" aria-live="polite" aria-atomic="true">
            {state.errors?.customerId &&
              state.errors.customerId.map((error: string) => (
                <p className="mt-2 text-sm text-red-500" key={error}>
                  {error}
                </p>
              ))}
          </div>
        </div>

        {/* Invoice Amount */}
        <div className="mb-4">
          <label htmlFor="amount" className="mb-2 block text-sm font-medium">
            Choose an amount
          </label>
          <div className="relative mt-2 rounded-md">
            <div className="relative">
              <input
                id="amount"
                name="amount"
                type="number"
                step="0.01"
                placeholder="Enter USD amount"
                className="peer block w-full rounded-md border border-gray-200 py-2 pl-10 text-sm outline-2 placeholder:text-gray-500"
                aria-describedby="amount-error"
              />
              <CurrencyDollarIcon className="pointer-events-none absolute left-3 top-1/2 h-[18px] w-[18px] -translate-y-1/2 text-gray-500 peer-focus:text-gray-900" />
            </div>
          </div>
          <div id="amount-error" aria-live="polite" aria-atomic="true">
            {state.errors?.amount &&
              state.errors.amount.map((error: string) => (
                <p className="mt-2 text-sm text-red-500" key={error}>
                  {error}
                </p>
              ))}
          </div>
        </div>

        {/* Invoice Status */}
        <fieldset aria-describedby="invoice-status-error">
          <legend className="mb-2 block text-sm font-medium">
            Set the invoice status
          </legend>
          <div className="rounded-md border border-gray-200 bg-white px-[14px] py-3">
            <div className="flex gap-4">
              <div className="flex items-center">
                <input
                  id="pending"
                  name="status"
                  type="radio"
                  value="pending"
                  className="h-4 w-4 cursor-pointer border-gray-300 bg-gray-100 text-gray-600 focus:ring-2"
                />
                <label
                  htmlFor="pending"
                  className="ml-2 flex cursor-pointer items-center gap-1.5 rounded-full bg-gray-100 px-3 py-1.5 text-xs font-medium text-gray-600"
                >
                  Pending <ClockIcon className="h-4 w-4" />
                </label>
              </div>
              <div className="flex items-center">
                <input
                  id="paid"
                  name="status"
                  type="radio"
                  value="paid"
                  className="h-4 w-4 cursor-pointer border-gray-300 bg-gray-100 text-gray-600 focus:ring-2"
                />
                <label
                  htmlFor="paid"
                  className="ml-2 flex cursor-pointer items-center gap-1.5 rounded-full bg-green-500 px-3 py-1.5 text-xs font-medium text-white"
                >
                  Paid <CheckIcon className="h-4 w-4" />
                </label>
              </div>
            </div>
            <div
              id="invoice-status-error"
              aria-live="polite"
              aria-atomic="true"
            >
              {state.errors?.status &&
                state.errors.status.map((error: string) => (
                  <p className="mt-2 text-sm text-red-500" key={error}>
                    {error}
                  </p>
                ))}
            </div>
          </div>
        </fieldset>
        <div id="form-error" aria-live="polite" aria-atomic="true">
          {state.message && (
            <p className="mt-2 text-sm text-red-500">{state.message}</p>
          )}
        </div>
      </div>
      <div className="mt-6 flex justify-end gap-4">
        <Link
          href="/dashboard/invoices"
          className="flex h-10 items-center rounded-lg bg-gray-100 px-4 text-sm font-medium text-gray-600 transition-colors hover:bg-gray-200"
        >
          Cancel
        </Link>
        <Button type="submit">
          {pending ? 'Creating...' : 'Create Invoice'}
        </Button>
      </div>
    </form>
  );
}

The actions ( action.ts )

'use server';

import { sql } from '@vercel/postgres';
import { revalidatePath } from 'next/cache';
import { redirect } from 'next/navigation';
import { z } from 'zod';

const FormSchema = z.object({
  id: z.string(),
  customerId: z.string({
    invalid_type_error: 'Please select a customer.',
  }),
  amount: z.coerce
    .number()
    .gt(0, { message: 'Please enter an amount greater than $0.' }),
  status: z.enum(['pending', 'paid'], {
    message: 'Please select an invoice status.',
  }),
  date: z.string(),
});

const CreateInvoice = FormSchema.omit({ id: true, date: true });
const UpdateInvoice = FormSchema.omit({ id: true, date: true });

export type State = {
  errors?: {
    customerId?: string[];
    amount?: string[];
    status?: string[];
  };
  message?: string | null;
};

export async function createInvoice(prevState: State, formData: FormData) {
  // Validate form fields using Zod
  const validatedFields = CreateInvoice.safeParse({
    customerId: formData.get('customerId'),
    amount: formData.get('amount'),
    status: formData.get('status'),
  });

  console.log(validatedFields);
  // If form validation fails, return errors early. Otherwise, continue.
  if (!validatedFields.success) {
    return {
      errors: validatedFields.error.flatten().fieldErrors,
      message: 'Missing Fields. Failed to Create Invoice.',
    };
  }

  // Prepare data for insertion into the database
  const { customerId, amount, status } = validatedFields.data;
  const amountInCents = amount * 100;
  const date = new Date().toISOString().split('T')[0];

  try {
    await sql`
      INSERT INTO invoices (customer_id, amount, status, date)
      VALUES (${customerId}, ${amountInCents}, ${status}, ${date})
    `;
  } catch (error) {
    // If a database error occurs, return a more specific error.
    return {
      message: 'Database Error: Failed to Create Invoice.',
    };
  }

  // Revalidate the cache for the invoices page and redirect the user.
  revalidatePath('/dashboard/invoices');
  redirect('/dashboard/invoices');
}

export async function updateInvoice(
  id: string,
  prevState: State,
  formData: FormData,
) {
  // Validate form fields using Zod
  const validatedFields = UpdateInvoice.safeParse({
    customerId: formData.get('customerId'),
    amount: formData.get('amount'),
    status: formData.get('status'),
  });

  console.log(validatedFields);
  // If form validation fails, return errors early. Otherwise, continue.
  if (!validatedFields.success) {
    return {
      errors: validatedFields.error.flatten().fieldErrors,
      message: 'Missing Fields. Failed to Update Invoice.',
    };
  }

  // Prepare data for insertion into the database
  const { customerId, amount, status } = validatedFields.data;
  const amountInCents = amount * 100;

  try {
    await sql`
        UPDATE invoices
        SET customer_id = ${customerId}, amount = ${amountInCents}, status = ${status}
        WHERE id = ${id}
      `;
  } catch (error) {
    return { message: 'Database Error: Failed to Update Invoice.' };
  }

  revalidatePath('/dashboard/invoices');
  redirect('/dashboard/invoices');
}

export async function deleteInvoice(id: string) {
  try {
    await sql`DELETE FROM invoices WHERE id = ${id}`;
    revalidatePath('/dashboard/invoices');
    return { message: 'Deleted Invoice.' };
  } catch (error) {
    return { message: 'Database Error: Failed to Delete Invoice.' };
  }
}

[eiffel205566]

@EdoanR hey, wanna try my solution and see if it works? By the way, the official documentaion is written in the way where failure on data validation on form submission will wipe out previously entered good data, it was written that way

https://github.com/vercel/next-learn/issues/845

[EdoanR]

@EdoanR hey, wanna try my solution and see if it works? By the way, the official documentaion is written in the way where failure on data validation on form submission will wipe out previously entered good data, it was written that way

845

I tried right now and it works! I had to change the State properties to work, only for the customerId for now, but seems easy to implement for the other fields too. I still wish there's a better way to do it, looks relatively simple, I will keep this issue opened for now.