Error in function argument

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
require_once 'Credentials/credentials.php';
require_once ("Entities/CoffeeEntity.php");
$coffee = new CoffeeModel($db);

var_dump( $coffee->GetCoffeeTypes() );
var_dump( $coffee->GetCoffeeByType('sometype') );
require_once ("Entities/CoffeeEntity.php");

//Contains database related code for the Coffee page.
class CoffeeModel {

    private $db;

    public function __construct(\PDO $db) {
        $this->db = $db;
    }

    public function GetCoffeeTypes() {
        $stmt = $this->db->query("SELECT DISTINCT type FROM coffee");
		
        return $stmt->fetchAll();
    }

    public function GetCoffeeByType($type) {
        $stmt = $this->db->prepare("SELECT name, type, price, roast, country, image, review FROM coffee WHERE type LIKE :type");
        $stmt->execute(['%' . $type . '%']);
		
        return $stmt->fetchAll(PDO::FETCH_CLASS, 'CoffeeEntity');
    }

}
?>

<?php

require_once 'Controller/CoffeeController.php';
$coffeeController = new CoffeeController();

if(isset($_POST['types']))
{
    //Fill page with coffees of the selected type
    $coffeeTables = $coffeeController->CreateCoffeeTables($_POST['types']);
}
else 
{
    //Page is loaded for the first time, no type selected -> Fetch all types
    $coffeeTables = $coffeeController->CreateCoffeeTables('%');
}

//Output page data
$title = 'Coffee overview';
$content = $coffeeController->CreateCoffeeDropdownList(). $coffeeTables;

include 'Template.php';
?>

<?php

require_once ("Model/CoffeeModel.php");

//Contains non-database related function for the Coffee page
class CoffeeController {

    function CreateCoffeeDropdownList() {
        $coffeeModel = new CoffeeModel();
        $result = "<form action = '' method = 'post' width = '200px'>
                    Please select a type: 
                    <select name = 'types' >
                        <option value = '%' >All</option>
                        " . $this->CreateOptionValues($coffeeModel->GetCoffeeTypes()) .
                "</select>
                     <input type = 'submit' value = 'Search' />
                    </form>";

        return $result;
    }

    function CreateOptionValues(array $valueArray) {
        $result = "";

        foreach ($valueArray as $value) {
            $result = $result . "<option value='$value'>$value</option>";
        }

        return $result;
    }
    
    function CreateCoffeeTables($types)
    {
        $coffeeModel = new CoffeeModel();
        $coffeeArray = $coffeeModel->GetCoffeeByType($types);
        $result = "";
        
        //Generate a coffeeTable for each coffeeEntity in array
        foreach ($coffeeArray as $key => $coffee) 
        {
            $result = $result .
                    "<table class = 'coffeeTable'>
                        <tr>
                            <th rowspan='6' width = '150px' ><img runat = 'server' src = '$coffee->image' /></th>
                            <th width = '75px' >Name: </th>
                            <td>$coffee->name</td>
                        </tr>
                        
                        <tr>
                            <th>Type: </th>
                            <td>$coffee->type</td>
                        </tr>
                        
                        <tr>
                            <th>Price: </th>
                            <td>$coffee->price</td>
                        </tr>
                        
                        <tr>
                            <th>Roast: </th>
                            <td>$coffee->roast</td>
                        </tr>
                        
                        <tr>
                            <th>Origin: </th>
                            <td>$coffee->country</td>
                        </tr>
                        
                        <tr>
                            <td colspan='2' >$coffee->review</td>
                        </tr>                      
                     </table>";
        }        
        return $result;
        
    }

}

?>