Custom Pagination in SilverStripe CMS

PrevNextPage

<?php

class CustomObject extends DataObject {

    private static $db = array(
        'Sort' => 'Int',
    );
    
    private static $default_sort = 'Sort ASC';

    public function PrevNextPage($mode = 'next', $loop_around = TRUE)
    {
        if ($mode==='next') {
            $sort = $this->Sort + 1;
            $dir = 'ASC';
        } else {
            $sort = $this->Sort - 1;
            $dir = 'DESC';
        }
    
        $page = self::get()->filter(array(
            'ParentID' => $this->ParentID,
            'Sort'     => $sort
        ))->First();
    
        if( ! $page && $loop_around )
        {
            $page = self::get()->filter(array(
                'ParentID' => $this->ParentID,
            ))->sort('Sort', $dir)->First();
        }
    
        return $page;
        
    }
    
}