5 Ways to Implement Email Validation in MUI

Validating emails in MUI is a common requirement for building robust forms. We'll explore five different ways to handle this, complete with working code. We will also look at the common pitfalls of these methods and see how Abstract API provides a more reliable solution for your application.

How to Implement Email Validation in MUI

Here are four common methods to validate email inputs in your MUI forms. Each approach has a different implementation, from native browser features to popular third-party form management libraries.

Browser-Level Validation via MUI TextField

This method leverages the fact that the MUI TextField component forwards props to the underlying HTML input element. By setting the input type to email, you activate the browser’s built-in validation for email addresses.

The component's onBlur event checks the input's validity state. The error and helperText props then reflect this state in the UI. This technique provides validation without extra libraries or regular expressions, as detailed in a muhimasri.com blog post.

<TextField type="email" required onBlur={e => setError(!e.target.validity.valid)} error={error} helperText={error && 'Invalid email'} />

A Custom HTML Pattern with the Native Validity API

For more specific validation, you can add a custom regex pattern. This approach pushes the pattern evaluation to the browser but still uses MUI's error and helperText props to show the result. The pattern is passed to the inputProps of the TextField.

The same onBlur event and validity check from the previous method apply here. This allows for stricter rules, such as an email from a specific domain. Form-level validation is also straightforward with `formRef.current.checkValidity()`, as shown in another muhimasri.com example.

<TextField label="Work e-mail" required inputProps={{pattern:'^[A-Za-z0-9._%+-]+@mycorp\\.com$'}} onBlur={e=>setError(!e.target.validity.valid)} … />

Schema Validation with Formik and Yup

This method combines Formik for form state management and Yup for schema-based validation. You define a validation schema with Yup that specifies the rules for your form fields, such as `string()`, `email()`, and `required()`.

The Formik component wraps your form and connects to the schema via the validationSchema prop. According to the Formik documentation, it manages the form's state, including values and errors. The MUI TextField's error and helperText props are then bound to Formik's `touched` and `errors` state, so validation messages appear only after a user interacts with the field.

const schema = Yup.object({ email: Yup.string().email().required() });
<Formik initialValues={{email:''}} validationSchema={schema} onSubmit={…}>
 {({errors,touched})=>(
   <TextField name="email" value={values.email} onChange={handleChange} error={touched.email&&Boolean(errors.email)} helperText={touched.email&&errors.email}/>
 )}
</Formik>

A Controlled Component with a Runtime Validator

This approach puts all validation logic inside your React component. You manage the input's value and error state with the `useState` hook. A library like `validator.js` or a custom function provides the validation logic.

The TextField's `onChange` handler triggers on every keystroke. Inside the handler, you update the email's value in the state and call the validation function to check it. The result of this check determines the boolean value for the error state, which in turn controls the TextField's error prop and helper text, a method found on restack.io.

import isEmail from 'validator/lib/isEmail';
const [email,setEmail]=useState(''); const [err,setErr]=useState(false);
<TextField value={email} onChange={e=>{const v=e.target.value; setEmail(v); setErr(!isEmail(v));}} error={err} helperText={err&&'Invalid email'}/>

Challenges of Email Validation in MUI

While these methods work, they introduce reliability and maintenance issues. Client-side validation alone often creates a false sense of security and can degrade the user experience with flawed checks.

• Browser-level validation defers to inconsistent rules across clients. An email may pass in one browser but fail in another, which makes the check unreliable and dependent on the user's environment.
• The MUI TextField component ignores the HTML pattern attribute. This forces complex workarounds for custom pattern validation and undermines the declarative logic of your forms, which makes advanced checks fragile.
• Browser autofill can update an input without a React state change. This desynchronizes the UI from the validation logic in controlled components and produces phantom pass or fail states that are hard to debug.
• Regex patterns, whether in custom HTML or with libraries like Yup, fail to cover all valid email formats. They cannot handle international domains or other edge cases, which results in false negatives for users.