How to create registration form in Wordpress without plugin?

Create registration form in Wordpress without plugin.

 

<?php

 /* Template Name: registration */

 

get_header();

?>

<div id="primary" class="content-area">

                <main id="main" class="site-main" role="main">

                                <?php

                                // Start the loop.

                                while ( have_posts() ) : the_post();

                                                // Include the page content template.

                                                get_template_part( 'template-parts/content', 'page' );

                                                // If comments are open or we have at least one comment, load up the comment template.

                                                if ( comments_open() || get_comments_number() ) {

                                                                comments_template();

                                                }

                                                // End of the loop.

                                endwhile;

                                ?>

                </main><!-- .site-main -->

           

</div><!-- .content-area -->

<?php

global $wpdb, $user_ID;  

if (!$user_ID) {  

   //All code goes in here.  

}  

else {  

   wp_redirect( home_url() ); exit;  

}

?>

<?php

$info = '';

if (isset($_POST['user_registeration']))

{

    //registration_validation($_POST['username'], $_POST['useremail']);

    global $reg_errors;

    $reg_errors = new WP_Error;

    $username=$_POST['username'];

    $useremail=$_POST['useremail'];

    $password=$_POST['password'];

    

    

    if(empty( $username ) || empty( $useremail ) || empty($password))

    {

        $reg_errors->add('field', 'Required form field is missing');

    }    

    if ( 6 > strlen( $username ) )

    {

        $reg_errors->add('username_length', 'Username too short. At least 6 characters is required' );

    }

    if ( username_exists( $username ) )

    {

        $reg_errors->add('user_name', 'The username you entered already exists!');

    }

    if ( ! validate_username( $username ) )

    {

        $reg_errors->add( 'username_invalid', 'The username you entered is not valid!' );

    }

    if ( !is_email( $useremail ) )

    {

        $reg_errors->add( 'email_invalid', 'Email id is not valid!' );

    }

    

    if ( email_exists( $useremail ) )

    {

        $reg_errors->add( 'email', 'Email Already exist!' );

    }

    if ( 5 > strlen( $password ) ) {

        $reg_errors->add( 'password', 'Password length must be greater than 5!' );

    }

    

    if (is_wp_error( $reg_errors ))

    { 

        foreach ( $reg_errors->get_error_messages() as $error )

        {

             $signUpError='<p style="color:#FF0000; text-aling:left;"><strong>ERROR</strong>: '.$error . '<br /></p>';

        } 

    }

    

    

    if ( 1 > count( $reg_errors->get_error_messages() ) )

    {

        // sanitize user form input

        global $username, $useremail;

        $username   =   sanitize_user( $_POST['username'] );

        $useremail  =   sanitize_email( $_POST['useremail'] );

        $password   =   esc_attr( $_POST['password'] );

        

        $userdata = array(

            'user_login'    =>   $username,

            'user_email'    =>   $useremail,

            'user_pass'     =>   $password

            );

        $user = wp_insert_user( $userdata );

if($user){

$info = 'You have been registered successfully';

}

    }

}

?>

 

  <?php echo $info; ?>

 <h3>Create your account</h3>

    <form action="" method="post" name="user_registeration">

        <label>Username <span class="error">*</span></label>  

        <input type="text" name="username" placeholder="Enter Your Username" class="text" required /><br />

        <label>Email address <span class="error">*</span></label>

        <input type="text" name="useremail" class="text" placeholder="Enter Your Email" required /> <br />

        <label>Password <span class="error">*</span></label>

        <input type="password" name="password" class="text" placeholder="Enter Your password" required /> <br />

        <input type="submit" name="user_registeration" value="SignUp" />

    </form>

    <?php if(isset($signUpError)){echo '<div>'.$signUpError.'</div>';}?>

<?php get_footer(); ?>