在rails/react应用程序中从联系人表单获取重复电子邮件

class Contact < ApplicationRecord
  validates_uniqueness_of :email
end

import React, { useState } from 'react';

const ContactForm = () => {
  const [email, setEmail] = useState('');

  const handleEmailChange = (event) => {
    setEmail(event.target.value);
  };

  const handleSubmit = (event) => {
    event.preventDefault();
    // 在这里可以将电子邮件发送到后端进行验证和保存
  };

  return (
    <form onSubmit={handleSubmit}>
      <input type="email" value={email} onChange={handleEmailChange} />
      <button type="submit">Submit</button>
    </form>
  );
};

export default ContactForm;

const handleSubmit = (event) => {
  event.preventDefault();

  fetch('/contacts', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ email }),
  })
    .then((response) => response.json())
    .then((data) => {
      // 处理后端返回的数据
    })
    .catch((error) => {
      // 处理错误
    });
};

class ContactsController < ApplicationController
  def create
    contact = Contact.new(contact_params)

    if contact.save
      render json: { success: true }
    else
      render json: { success: false, errors: contact.errors.full_messages }
    end
  end

  private

  def contact_params
    params.require(:contact).permit(:email)
  end
end