wishlist_settings_save

Use this code to create a new tab on the wishlist setting page.

add_action('wishlist_settings_tabs', 'wishlist_settings_tabs_custom');

function wishlist_settings_tabs_custom($settings_tab)
{
    $current_tab = isset($_REQUEST['tab']) ? sanitize_text_field($_REQUEST['tab']) : 'general';

    $settings_tab[] = array(
        'id' => 'custom',
        'title' => sprintf(__('%s custom', 'wishlist'), '<i class="fas fa-hands-helping"></i>'),
        'priority' => 95,
        'active' => ($current_tab == 'custom') ? true : false,
    );

    return $settings_tab;
}

Then use this code to generate some options on the newly created tab.

add_action('wishlist_settings_content_custom', 'wishlist_settings_content_custom');

if (!function_exists('wishlist_settings_content_custom')) {
    function wishlist_settings_content_custom($tab)
    {
        $settings_tabs_field = new settings_tabs_field();
        $wishlist_settings = get_option('wishlist_settings');

        $custom_option = isset($wishlist_settings['custom']['custom_option']) ? $wishlist_settings['custom']['custom_option'] : '';

?>
        <div class="section">
            <div class="section-title"><?php echo __('Custom tab title', 'post-grid'); ?></div>
            <p class="description section-description"><?php echo __('Custom tab details', 'post-grid'); ?></p>

            <?php
            $args = array(
                'id'        => 'custom_option',
                'parent'        => 'wishlist_settings[custom]',
                'title'        => __('Custom Option title', 'wishlist'),
                'details'    => __('Custom option details.', 'wishlist'),
                'type'        => 'text',
                'value'        => $custom_option,
                'default'        => '',
                'placeholder' => __('', 'wishlist'),
            );
            $settings_tabs_field->generate_field($args);
            ?>
        </div>
    <?php
    }
}

Now, add this code to save the custom setting to merge with our default wishlist setting.

add_action('wishlist_settings_save', 'wishlist_settings_save_custom');

function wishlist_settings_save_custom()
{
    $wishlist_settings = isset($_POST['wishlist_settings']) ?  wishlist_recursive_sanitize_arr($_POST['wishlist_settings']) : array();

    $custom_settings = isset($_POST['custom']) ?  ($_POST['custom']) : '';
    $wishlist_settings = array_merge($wishlist_settings, $custom_settings);

    update_option('wishlist_settings', $custom_settings);
}