run function from class on mysql array results

Hello,

I think I've been staring at this too long and now cannot see it straight anymore so another pair of eyes would be greatly appreciated.

I have the below code that pulls a result from mysql and puts it into an array. I now need to run a function from my class on one of the items in the array since I am using smarty to template and cannot call the function from the template or shouldn't anyway.

<?php

ini_set('display_errors', 1);
error_reporting(E_ALL);

include ('classes/TrackingBoardClass.php');
include ('functions.inc.php');

$clientID = "1";


$TrackingClass = new TrackingBoardClass();
$results = $TrackingClass->GetBoardResults($clientID);
if ($results != "") {
    while ($row2 = mysqli_fetch_assoc($results)) {

        $boardresults[] = $row2['priorityID'];
    }
}

//print_r($boardresults);

foreach ($boardresults as $value) {
    echo $TrackingClass->GetPriority($clientID, $value)."<br>";
}

?>

The $TrackingClass->GetPriority is the function that I am trying to run on the results, but I get error: Object of class mysqli_result could not be converted to string.

Any help or insights would be greatly appreciated. Thank you!