👀 Views: 81 💬 Answers: 1 📅 Created: 2025-06-13

next.js forms api javascript

I'm a bit lost with I've spent hours debugging this and I'm working on a personal project and I'm currently developing a Next.js 13 application and facing an issue with form submission where I'm trying to send nested objects to an API route... The form collects user data, which includes an array of addresses for each user, and when I submit the form, I'm receiving a 500 error from the server. Here's the form component I'm using: ```javascript import { useState } from 'react'; const UserForm = () => { const [formData, setFormData] = useState({ name: '', email: '', addresses: [{ street: '', city: '' }], }); const handleChange = (e) => { const { name, value } = e.target; setFormData({ ...formData, [name]: value, }); }; const handleAddressChange = (index, e) => { const { name, value } = e.target; const newAddresses = [...formData.addresses]; newAddresses[index] = { ...newAddresses[index], [name]: value }; setFormData({ ...formData, addresses: newAddresses }); }; const handleSubmit = async (e) => { e.preventDefault(); const response = await fetch('/api/users', { method: 'POST', headers: { 'Content-Type': 'application/json', }, body: JSON.stringify(formData), }); if (!response.ok) { console.error('Error submitting form:', response.statusText); } }; return ( <form onSubmit={handleSubmit}> <input type="text" name="name" value={formData.name} onChange={handleChange} placeholder="Name" /> <input type="email" name="email" value={formData.email} onChange={handleChange} placeholder="Email" /> {formData.addresses.map((address, index) => ( <div key={index}> <input type="text" name="street" value={address.street} onChange={(e) => handleAddressChange(index, e)} placeholder="Street" /> <input type="text" name="city" value={address.city} onChange={(e) => handleAddressChange(index, e)} placeholder="City" /> </div> ))} <button type="submit">Submit</button> </form> ); }; export default UserForm; ``` On the server side, I have this Next.js API route set up: ```javascript // pages/api/users.js export default async function handler(req, res) { if (req.method === 'POST') { const { name, email, addresses } = req.body; try { // Simulating a database save operation // Here I would normally call a database function to save the user if (!name || !email || !Array.isArray(addresses)) { throw new Error('Invalid data'); } res.status(200).json({ message: 'User created', data: req.body }); } catch (error) { console.error('Error saving user:', error); res.status(500).json({ message: 'Internal Server Error' }); } } else { res.setHeader('Allow', ['POST']); res.status(405).end(`Method ${req.method} Not Allowed`); } } ``` I've logged the data being sent to the API, and it looks correct: ```json { "name": "John Doe", "email": "john@example.com", "addresses": [ { "street": "123 Main St", "city": "Anytown" } ] } ``` Despite this, I keep encountering a 500 error. I've tried checking for the possible issues in my API handler, and I even added logging to see if the data is reaching the server as expected. The error message in the console indicates an 'Invalid data' issue, but I’ve confirmed that the data validation should pass. What could be causing this 500 error, and how can I resolve it? Any insights would be greatly appreciated! What am I doing wrong? This issue appeared after updating to Javascript 3.11. Am I approaching this the right way?