register-wp

<?php

/*
  Plugin Name: Custom Registration
  Plugin URI: http://code.tutsplus.com
  Description: Updates user rating based on number of posts.
  Version: 1.0
  Author: Agbonghama Collins
  Author URI: http://tech4sky.com
 */

function custom_registration_function() {
    if (isset($_POST['submit'])) {
        registration_validation(
        $_POST['username'],
        $_POST['password'],
        $_POST['email']
        );

        // sanitize user form input
        global $username, $password, $email;
        $username   =   sanitize_user($_POST['username']);
        $password   =   esc_attr($_POST['password']);
        $email      =   sanitize_email($_POST['email']);

        // call @function complete_registration to create the user
        // only when no WP_error is found
        complete_registration(
        $username,
        $password,
        $email
        );
    }

    registration_form(
        $username,
        $password,
        $email
        );
}

function registration_form( $username, $password, $email ) {
    echo '
    <style>
    div {
        margin-bottom:2px;
    }

    input{
        margin-bottom:4px;
    }
    </style>
    ';

    echo '
    <form action="' . $_SERVER['REQUEST_URI'] . '" method="post" class="needs-validation" novalidate>

    <div class="form-group input-icon-left m-b-10">
        <i class="fa fa-user"></i>
        <input type="text" name="username" class="form-control form-control-secondary" placeholder="Username" value="' . (isset($_POST['username']) ? $username : null) . '" required>
        <small class="form-text">This field can not be blank.</small>
    </div>
    <div class="form-group input-icon-left m-b-10">
        <i class="fa fa-envelope"></i>
        <input type="email" name="email" class="form-control form-control-secondary"  placeholder="Email Address" value="' . (isset($_POST['email']) ? $email : null) . '" required>
        <small class="form-text">This field can not be blank.</small>
    </div>
    <div class="divider"><span>Security</span></div>
    <div class="form-group input-icon-left m-b-10">
      <i class="fa fa-lock"></i>
      <input type="password" name="password" class="form-control form-control-secondary" placeholder="Password" value="' . (isset($_POST['password']) ? $password : null) . '" required>
      <small class="form-text">This field can not be blank.</small>
    </div>
    <div class="divider"><span>Terms of Service</span></div>
    <div class="form-group">
        <label class="custom-control custom-checkbox custom-checkbox-primary custom-checked">
        <input type="checkbox" class="custom-control-input" checked="">
        <span class="custom-control-indicator"></span>
        <span class="custom-control-description">Subscribe to weekly newsletter</span>
    </label>
    <div class="form-group">
        <label class="custom-control custom-checkbox custom-checkbox-primary">
            <input type="checkbox" class="custom-control-input" required>
            <span class="custom-control-indicator"></span>
            <span class="custom-control-description">Accept <a href="#" data-toggle="modal" data-target="#terms">terms of service</a></span>
        </label>
    </div>
    <div class="divider"><span>I am not a robot</span></div>
    <div class="form-group g-recaptcha-outer">
      <script src="https://www.google.com/recaptcha/api.js"></script>
      <div class="g-recaptcha" data-sitekey="6Le5b0QUAAAAAHD5sgGsM2_cUYSAoyU6j3RREU4O"></div>
    </div>
    <button type="submit" name="submit" class="btn btn-primary m-t-10 btn-block">Complete Registration</button>
    </form>
    ';
}

function registration_validation( $username, $password, $email )  {
    global $reg_errors;
    $reg_errors = new WP_Error;

    if ( empty( $username ) || empty( $password ) || empty( $email ) ) {
        $reg_errors->add('field', 'Required form field is missing');
    }

    if ( strlen( $username ) < 4 ) {
        $reg_errors->add('username_length', 'Username too short. At least 4 characters is required');
    }

    if ( username_exists( $username ) )
        $reg_errors->add('user_name', 'Sorry, that username already exists!');

    if ( !validate_username( $username ) ) {
        $reg_errors->add('username_invalid', 'Sorry, the username you entered is not valid');
    }

    if ( strlen( $password ) < 6 ) {
        $reg_errors->add('password', 'Password length must be greater than 6');
    }

    if ( !is_email( $email ) ) {
        $reg_errors->add('email_invalid', 'Email is not valid');
    }

    if ( email_exists( $email ) ) {
        $reg_errors->add('email', 'Email Already in use');
    }
}

    if ( is_wp_error( $reg_errors ) ) {

        foreach ( $reg_errors->get_error_messages() as $error ) {
            echo '<div>';
            echo '<strong>ERROR</strong>:';
            echo $error . '<br/>';

            echo '</div>';
        }
    }

function complete_registration() {
    global $reg_errors, $username, $password, $email;
    if ( count($reg_errors->get_error_messages()) < 1 ) {
        $userdata = array(
        'user_login'    =>  $username,
        'user_email'    =>  $email,
        'user_pass'     =>  $password,
        );
        $user = wp_insert_user( $userdata );
        echo 'Registration complete. Goto <a href="' . get_site_url() . '/wp-login.php">login page</a>.';
    }
}

// Register a new shortcode: [cr_custom_registration]
add_shortcode('cr_custom_registration', 'custom_registration_shortcode');

// The callback function that will replace [book]
function custom_registration_shortcode() {
    ob_start();
    custom_registration_function();
    return ob_get_clean();
}