Create Custom WordPress User Roles

    // To add the new role, using 'international' as the short name and
    // 'International Blogger' as the displayed name in the User list and edit page:
  
    add_role('international', 'International Blogger', array(
        'read' => true, // True allows that capability, False specifically removes it.
        'edit_posts' => true,
        'delete_posts' => true,
        'edit_published_posts' => true,
        'publish_posts' => true,
        'edit_files' => true,
        'import' => true,
        'upload_files' => true //last in array needs no comma!
    ));
   
     
    // To remove one outright or remove one of the defaults:
    /*
    remove_role('international');
    */

 

WordPress limit Comment Length

add_filter( 'preprocess_comment', 'jeba_wp_comment_length' );

function jeba_wp_comment_length($comment) {
if ( strlen( $comment['comment_content'] ) > 4000 ) {
wp_die('Comment is too long. Please keep your comment under 4000 characters.');
}
if ( strlen( $comment['comment_content'] ) < 90 ) {
wp_die('Comment is too short. Please use at least 90 characters.');
}
return $comment;
}

Note: Here can change comment length 4000 and 90 characters.

Ajax wordpress login modal

function jeba_theme_jquery_wp() {
?>
<form id="login" action="login" method="post">
<h1>Site Login</h1><br/>
<p class="status"></p>
<label for="username">Username</label>
<input id="username" type="text" name="username"><br/>
<label for="password">Password</label>
<input id="password" type="password" name="password"><br/>
<a class="lost" href="<?php echo wp_lostpassword_url(); ?>">Lost your password?</a><br/><br/>
<input class="submit_button" type="submit" value="Login" name="submit">
<a class="close" href="">(close)</a>
<?php wp_nonce_field( 'ajax-login-nonce', 'security' ); ?>
</form>
<style>

form#login {
background-color: gold;
color: #000;
display: none;
left: 50%;
margin-left: -200px;
padding: 40px 25px 25px;
position: fixed;
top: 200px;
width: 350px;
z-index: 999;
}

form#login p.status{
display: none;
}

.login_overlay {
background-color: #f6f6f6;
height: 100%;
left: 0;
opacity: 0.9;
position: fixed;
top: 0;
width: 100%;
z-index: 998;
}

</style>

<?php
}
add_action('wp_footer', 'jeba_theme_jquery_wp');

function ajax_login_init(){

    wp_register_script('ajax-login-script', get_template_directory_uri() . '/ajax-login-script.js', array('jquery') );
    wp_enqueue_script('ajax-login-script');

    wp_localize_script( 'ajax-login-script', 'ajax_login_object', array(
        'ajaxurl' => admin_url( 'admin-ajax.php' ),
        'redirecturl' => home_url(),
        'loadingmessage' => __('Sending user info, please wait...')
    ));

    // Enable the user with no privileges to run ajax_login() in AJAX
    add_action( 'wp_ajax_nopriv_ajaxlogin', 'ajax_login' );
}

// Execute the action only if the user isn't logged in
if (!is_user_logged_in()) {
    add_action('init', 'ajax_login_init');
}
function ajax_login(){

    // First check the nonce, if it fails the function will break
    check_ajax_referer( 'ajax-login-nonce', 'security' );

    // Nonce is checked, get the POST data and sign user on
    $info = array();
    $info['user_login'] = $_POST['username'];
    $info['user_password'] = $_POST['password'];
    $info['remember'] = true;

    $user_signon = wp_signon( $info, false );
    if ( is_wp_error($user_signon) ){
        echo json_encode(array('loggedin'=>false, 'message'=>__('Wrong username or password.')));
    } else {
        echo json_encode(array('loggedin'=>true, 'message'=>__('Login successful, redirecting...')));
    }

    die();
}

Save below code as ajax-login-script.js and use location correctly with ajax_login_init function.

jQuery(document).ready(function($) {

    // Show the login dialog box on click
    $('a#show_login').on('click', function(e){
        $('body').prepend('<div class="login_overlay"></div>');
        $('form#login').fadeIn(500);
        $('div.login_overlay, form#login a.close').on('click', function(){
            $('div.login_overlay').remove();
            $('form#login').hide();
        });
        e.preventDefault();
    });

    // Perform AJAX login on form submit
    $('form#login').on('submit', function(e){
        $('form#login p.status').show().text(ajax_login_object.loadingmessage);
        $.ajax({
            type: 'POST',
            dataType: 'json',
            url: ajax_login_object.ajaxurl,
            data: { 
                'action': 'ajaxlogin', //calls wp_ajax_nopriv_ajaxlogin
                'username': $('form#login #username').val(), 
                'password': $('form#login #password').val(), 
                'security': $('form#login #security').val() },
            success: function(data){
                $('form#login p.status').text(data.message);
                if (data.loggedin == true){
                    document.location.href = ajax_login_object.redirecturl;
                }
            }
        });
        e.preventDefault();
    });

});

Usage:

<?php if (is_user_logged_in()) { ?>
<a class="login_button" href="<?php echo wp_logout_url( home_url() ); ?>">Logout</a>
<?php } else { ?>
<a class="login_button" id="show_login" href="">Login</a>
<?php } ?>