Customizing the WordPress Comment Form with PHP

Customizing the WordPress Comment Form

Custom Code Solution

You can customize the comment form by using the comment_form_default_fields and comment_form_defaults filters in your theme's functions.php file.

Change the default comment form fields (name, email, website):

function modify_comment_form_fields($fields) {
    // Remove website field
    unset($fields['url']);
    
    // Modify name field
    $fields['author'] = '<p class="comment-form-author">' . 
        '<label for="author">Name *</label>' .
        '<input id="author" name="author" type="text" required="required" />' .
        '</p>';
    
    // Modify email field
    $fields['email'] = '<p class="comment-form-email">' .
        '<label for="email">Email *</label>' .
        '<input id="email" name="email" type="email" required="required" />' .
        '</p>';
    
    return $fields;
}
add_filter('comment_form_default_fields', 'modify_comment_form_fields');

Customize the main comment textarea and form settings:

function modify_comment_form($defaults) {
    $defaults['title_reply'] = 'Leave a Comment';
    $defaults['comment_field'] = '<p class="comment-form-comment">' .
        '<label for="comment">Your Message *</label>' .
        '<textarea id="comment" name="comment" rows="8" required="required"></textarea>' .
        '</p>';
    $defaults['label_submit'] = 'Post Comment';
    $defaults['comment_notes_before'] = '';
    $defaults['comment_notes_after'] = '';
    
    return $defaults;
}
add_filter('comment_form_defaults', 'modify_comment_form');

Add custom CSS styling (add to your theme's style.css):

.comment-form-author,
.comment-form-email,
.comment-form-comment {
    margin-bottom: 20px;
}

.comment-form input[type="text"],
.comment-form input[type="email"],
.comment-form textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.form-submit input[type="submit"] {
    background: #333;
    color: #fff;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

Plugin Alternative

If you prefer a plugin solution, consider:

1. wpDiscuz - Advanced comment system with custom forms
2. Comments – wpForo - Modern comment layouts and styling

Notes

• Place the PHP code in your theme's functions.php file
• Place CSS in your theme's style.css file or in the WordPress Customizer
• The code is adaptable - modify field labels, classes, and HTML structure as needed
• Use WordPress's built-in comment_form() function in your template files
• Test thoroughly after implementation to ensure proper form submission

For advanced validation or additional fields, you'll need to use the preprocess_comment hook to handle the form submission.