Custom datasource Member roles

data.dsRoles.php

<?php

class datasourcedsRoles extends SectionDatasource
{
    public $dsParamROOTELEMENT = 'dsRoles';
   
    public $dsParamCACHE = -1;

    public $dsParamFILTERS = array(
       
    );

    public $dsParamINCLUDEDELEMENTS = array(
           );

    public function __construct($env = null, $process_params = true)
    {
        parent::__construct($env, $process_params);
        $this->_dependencies = array();
    }

    public function about()
    {
        return array(
            'name' => 'dsroles',
            'author' => array(
                'name' => 'Wannes Debusschere',
                'website' => 'http://localhost/application',
                'email' => 'info@e-xperience.be'),
            'version' => 'Symphony 2.7.6',
            'release-date' => '2018-05-10T11:35:12+00:00'
        );
    }

    public function getSource()
    {
           }

    public function allowEditorToParse()
    {
        return false;
    }

    public function execute(array &$param_pool = null)
    {
                  $result = new XMLElement($this->dsParamROOTELEMENT);

            $roles = Symphony::Database()->fetch(sprintf("
                SELECT * 
                FROM sym_members_roles
                ORDER BY name ASC
            "));

        
        $pagination = new XMLElement('pagination', '', array(
                    'total-entries' => count($roles) ));
                
        $result->appendChild($pagination);
        
        
            foreach($roles as $role){
                $item = new XMLElement('entry', General::sanitize($role['name']), array(
                    'id' => $role['id'],
                    'handle' => $role['handle']
                ));
                $result->appendChild($item);
            }

            return $result;
          }
}