Why is the $this->getOrders method always returns a null object in this code Magento

Question

I am new to magento.I am trying to create a view for the purchase history for users.Already there is a page to display this(As I am using a template).But as a experiment I tried to create a new page with the same content.As my first step. I created a new php block and then I copied same the content from the old purchase history file to the new one(Without any change).Then I called that block in a cms page.But when I called the url of the new page,It gives this error

Fatal error: Call to a member function getSize() on null in /home/bvbellpm/public_html/newtrades/app/design/frontend/base/default/template/customer/form/purchasehistory.phtml on line

This is the code which I used to display the history

<?php echo $this->getMessagesBlock()->getGroupedHtml() ?>
<?php $_orders = $this->getOrders(); ?>
<div class="page-title">
    <h1><?php echo $this->__('My Orders') ?></h1>
</div>
<?php echo $this->getPagerHtml(); ?>
<?php if($_orders->getSize()>0): ?>
<table class="data-table" id="my-orders-table">
    <thead>
        <tr>
            <th><?php echo $this->__('Order #') ?></th>
            <th><?php echo $this->__('Date') ?></th>
            <th><?php echo $this->__('Ship To') ?></th>
            <th><span class="nobr"><?php echo $this->__('Order Total') ?></span></th>
            <th><span class="nobr"><?php echo $this->__('Order Status') ?></span></th>
            <th>&nbsp;</th>
        </tr>
    </thead>
    <tbody>
        <?php $_odd = ''; ?>
        <?php foreach ($_orders as $_order): ?>
        <tr>
            <td><?php echo $_order->getRealOrderId() ?></td>
            <td><span class="nobr"><?php echo $this->formatDate($_order->getCreatedAtStoreDate()) ?></span></td>
            <td><?php echo $_order->getShippingAddress() ? $this->htmlEscape($_order->getShippingAddress()->getName()) : '&nbsp;' ?></td>
            <td><?php echo $_order->formatPrice($_order->getGrandTotal()) ?></td>
            <td><em><?php echo $_order->getStatusLabel() ?></em></td>
            <td class="a-center">
                <span class="nobr"><a href="<?php echo $this->getViewUrl($_order) ?>"><?php echo $this->__('View Order') ?></a>
                    <?php /*<span class="separator">|</span><a href="<?php echo $this->getTrackUrl($_order) ?>"><?php echo $this->__('Track Order') ?></a>&nbsp;*/ ?>
                    <?php if ($this->helper('sales/reorder')->canReorder($_order)) : ?>
                    <span class="separator">|</span> <a href="<?php echo $this->getReorderUrl($_order) ?>" class="link-reorder"><?php echo $this->__('Reorder') ?></a>
                <?php endif ?>
                </span>
            </td>
        </tr>
        <?php endforeach; ?>
    </tbody>
</table>

But this same code works fine in the old purchase history file.Why is this not working in the new page? .I think $this->getOrders() is returning a null object.But it is working fine in the old page.As far as I know $this->getOrders() is a magic method in Magento.So I think it can be used any where.Can someone explain me the reason for this odd behavior?

Answer 1

As you told us that you are new I would like to tell you about block and template mapping

Every template assign to a block so in template (phtml) file $this represent block class

so in your block class should have to contain that method getOrders other wise you will not get the data

You can look at this blog and learn how you bind blocks with template via layout http://excellencemagentoblog.com/blog/2011/09/22/magento-part2-series-layouts/

Answer 2

Use this code

<?php if ($_orders && count($_orders)) : ?> 

Instea of this code`

<?php if($_orders->getSize()>0): ?>`