How can I implement async validation in Vue 3?

How can I implement async validation in Vue 3?

You can use the vuelidate library or Vue's built-in validation features. Would you like a code example?

Yes, please provide a code example using vuelidate.

Sure! First, install vuelidate: npm install @vuelidate/core @vuelidate/validators. Then, you can set up your validation like this:

import useVuelidate from '@vuelidate/core';
import { required, email } from '@vuelidate/validators';

export default {
  setup() {
    const state = reactive({ email: '' });
    const rules = { email: { required, email } };
    const v$ = useVuelidate(rules, state);

    return { state, v$ };
  }
};

This sets up a reactive state with validation rules for an email field.

How do I handle the async part of the validation?

For async validation, you can create a custom validator. For example:

import { required, email } from '@vuelidate/validators';

const asyncEmail = async (value) => {
  const response = await checkEmailExists(value);
  return !response.exists;
};

const rules = { email: { required, email, async: asyncEmail } };

This will check if the email exists asynchronously.