Magento – get session in template file

On our cPanel boxes, missing assets were serving the entire Magento page.

cPanel's defaults to ErrorDocument 404 /404.shtml but /404.shtml doesn't exist in Magento's document root, so the .htaccess gets executed again and redirects /404.shtml to index.php (using mod_rewrite).

Magento's default .htaccess should specify 404, 500, and other error handlers explicitly.

To fix this beahviour, we added the following to our .htaccess:

ErrorDocument 404 /errors/404.php

We probably should also add 500s as well:

ErrorDocument 500 /errors/500.php

The cleanest way to do this is will use observers and custom layout XML. For that you will need to create your own extension. Inchoo has a nice hello world article that should get you started and you can read more about observers in this Magento Board post.

You will need to hook the controller_action_layout_load_before event. Add this to your config.xml.

<controller_action_layout_load_before>
    <observers>
        <[module]>
            <type>singleton</type>
            <class>[module]/observer</class>
            <method>addLayoutHandleObserver</method>
        </[module]>
    </observers>
</controller_action_layout_load_before>

Your Observer would use your code to check for the specific product and if present add a layout handle to the generate Layout XML. This will enable us to target it from a layout xml file.

class [Namespace]_[Module]_Model_Observer
{
    public function addLayoutHandleObserver(Varien_Event_Observer $observer)
    {

        $items = Mage::getSingleton('checkout/session')->getQuote()->getAllItems();

        $logo_cart = false;
        foreach ($items as $_item) 
        {
            $get_attributes = $_item->getProduct()->getTypeInstance(true)->getOrderOptions($_item->getProduct());
            $attributes = $get_attributes['attributes_info'];
            foreach($attributes as $attribute) {
                if($attribute['value'] == 'Has Logo') {
                    $logo_cart = true;
                    break;
                }
            }
           if ($logo_cart) break;
        }

        if ($logo_cart)
        {
            $layout = $observer->getAction()->getLayout();
            $layout->getUpdate()->addHandle('checkout_has_logo');
            $layout->generateXml();
        }

        return $this;
    }
}

Now we can add some custom layout updates from, for example, the local.xml.

<checkout_has_logo>
    <reference name="checkout.onepage">
        <action method="setTemplate"><template>checkout/onepage_logo.phtml</template></action>
    </reference>
</checkout_has_logo>