Building a Frontend Registration Form in WordPress

• Prerequisites
• Step 1: Create a Registration Form
• Step 2: Add the Page Template to a New Page
• Step 3: Validate Form Data
• Step 4: Create New User

WordPress comes with a built-in user registration form. However, it's rather basic and may not meet your needs. In this tutorial, we'll walk you through how to create a custom user registration form in the frontend, without using any plugin.

This tutorial is one of a number of tutorials we are creating in order to build your own frontend authentication in WordPress. To date we have discussed how to create a frontend login form on WordPress.

¶Prerequisites

• Basic knowledge of PHP and HTML.
• An active WordPress website where you can add custom code.

¶Step 1: Create a Registration Form

The first step is to create a custom page template that will display our registration form. In your active theme's directory, create a new PHP file custom-register.php.

Paste the following code into custom-register.php:

<?php
/*
Template Name: Custom Register
*/

// If the form is submitted
if($_SERVER['REQUEST_METHOD'] == 'POST') {
    // We'll process the form in the next steps
}
get_header(); 
?>

<form method="post" action="<?php echo $_SERVER['REQUEST_URI']; ?>">
    <div>
        <label for="username">Username</label>
        <input type="text" name="username" id="username">
    </div>

    <div>
        <label for="password">Password</label>
        <input type="password" name="password" id="password">
    </div>

    <div>
        <label for="email">Email</label>
        <input type="email" name="email" id="email">
    </div>

    <input type="submit" name="submit" value="Register">
</form>

<?php get_footer(); ?>

This is a basic form with fields for the username, password, and email. You can add more fields as needed.

¶Step 2: Add the Page Template to a New Page

In the WordPress admin, create a new page, and in the Page Attributes meta box, set the template to 'Custom Register'. Publish the page and view it to see your form.

¶Step 3: Validate Form Data

Now, we need to validate the form data when it's submitted. Inside the if condition where we check for a POST request, add the following:

// Check username is present and doesn't already exist
$username = sanitize_user( $_POST['username'] );
if ( ! $username || username_exists( $username ) ) {
    echo 'Please enter a valid username';
    return;
}

// Check email address is present and valid
$email = sanitize_email( $_POST['email'] );
if ( ! $email || ! is_email( $email ) ) {
    echo 'Please enter a valid email address';
    return;
}

// Check password is valid
$password = $_POST['password'];
if ( ! $password ) {
    echo 'Please enter a password';
    return;
}

¶Step 4: Create New User

If the form data is valid, we can create a new user with wp_create_user(). Add the following at the end of the if condition:

// All validation checks passed successfully. Proceed to create the user.
$user_id = wp_create_user( $username, $password, $email );

if ( ! is_wp_error( $user_id ) ) {
    echo 'Your registration was successful.';
} else {
    echo 'There was an error in the registration process.';
}

In this tutorial, you've created a custom registration form that validates user input and creates a new user. This is a basic form but serves as a great starting point for more complex registration forms.