Magento2 - Can't get Orders from Block

Question

I'm trying to extract some datas from magento. Here, the orders. I search on the net and I don't understand why I always got null orders.

I have a Block like this:

namespace TATA\TOTO\Block\Extraction;

use \Magento\Framework\View\Element\Template\Context;
use \Magento\Sales\Model\ResourceModel\Order\CollectionFactory as OrderCollectionFactory;
use \Magento\Sales\Model\ResourceModel\Order\Collection as OrderCollection;
use \TATA\TOTO\Block\AbstractExtractionBlock;

/**
 * Order Block
 */
class Order extends AbstractExtractionBlock
{
    /* @var OrderCollectionFactory $_orderCollectionFactory */
    protected $_orderCollectionFactory;

    /* @var OrderCollection $_orderCollection */
    protected $_orderCollection;

    /**
     * Order constructor.
     *
     * @param Context $context
     * @param OrderCollectionFactory $orderCollectionFactory
     * @param array $data
     */
    public function __construct(
        Context $context,
        OrderCollectionFactory $orderCollectionFactory,
        array $data = [])
    {
        $this->_orderCollectionFactory = $orderCollectionFactory;
        $this->_orderCollection = null;

        parent::__construct($context, $data);null);
    }

    /**
     * Get the Order Collection
     *
     * @return OrderCollection
     */
    public function getOrderCollection()
    {
        if (is_null($this->_orderCollection)) {
            $this->_orderCollection = $this->_orderCollectionFactory->create()
                ->addFieldToSelect('*');

            $this->setPaginationParameters($this->_orderCollection);
        }
        return $this->_orderCollection;
    }
}

The Block extends from an abstract Block which implement an Interface. I'm not sure you need all of this. See the Interface below:

namespace TATA\TOTO\Block;

use \Magento\Framework\Data\Collection;

/**
 * Extraction Block Interface
 */
interface ExtractionBlockInterface
{
    /**
     * Get the pagination parameters into the respective vars.
     */
    public function getPaginationParameters();

    /**
     * Set the pagination parameters.
     *
     * @param Collection $collection
     * @return Collection
     */
    public function setPaginationParameters(Collection $collection);

    /**
     * Escape the param form HTML and delete all newline char.
     *
     * @param string $param
     * @return string
     */
    public function frontendEscape($param);
}

The Controller is classic and the template looks like this:

use \Magento\Sales\Model\ResourceModel\Order\Collection as OrderCollection;
use \Magento\Sales\Model\Order;

/* @var OrderCollection $orders */
$orders = $this->getProductCollection();
echo 'ORDER_ID|CUST_ID|PRODUCT_ID|REFERENCE|UNIT_PRICE|CURRENCY|QUANTITY|DATE<br>';

if (empty($orders)) return; // Prevent the null value for foreach.

// Never goes there because $orders is null

/* @var Order $order */
foreach ($orders as $order) {
    echo $order->getId(); //Trying to display the Id.
}

Do you see an mistake I've made?

Answer 1

Seem that your collection is wrong:

Replace:

$orders = $this->getProductCollection(); 

by

$orders = $this->getOrderCollection();