Get the next order increment id during checkout? - magento

Question

I am developing a custom payment gateway. It uses OrderIncrementID to identify which Order was the payment made for. I have every functionality running after the Order has been placed, i.e. after checkout, except one in the checkout page itself.
In the checkout page, Order was not created, getting an OrderIncrementID seems very difficult. We have to overwrite the order creation in the checkout such that it will be created after the payment method selection which sounds very complicated and dangerous to overwrite the flow. An alternative is to use QuoteID, but the tradeoff is that I have to implement a convertion from QuoteID to OrderIncrementID.
What can I do in this case to get an OrderIncrementID in the checkout page? especially after the payment method selection

Answer 1

You actually already have a reserved order id on the quote.
You just have to do :
$quote = Mage::getSingleton('checkout/session')->getQuote();
$quote->getReservedOrderId(); // this will be your order_increment_id

Answer 2

I developed bellow code to get next increment ID
I am not sure this will give correct result always.
But, this can help you
Please bellow code in any resource model to call
For example : place code in Names_Test_Model_Resource_Test class
public function getNextIncrementId(){
$store = Mage::app()->getStore();
$resource = Mage::getSingleton('core/resource');
$readConnection = $resource->getConnection('core_read');
$entityStoreTable = $resource->getTableName('eav_entity_store');
$entityTypeTable = $resource->getTableName('eav_entity_type');
$selectEntity = $readConnection->select()->from($entityTypeTable, "*")
->where("entity_type_code = 'order'");
$entityTypeRow = $readConnection->fetchRow($selectEntity);
if(isset($entityTypeRow['entity_type_id']) && $entityTypeRow['entity_type_id'] > 0){
$orderEntityTypeId = $entityTypeRow['entity_type_id'];
$entityStoreSelect = $readConnection->select()->from($entityStoreTable, "*")
->where("store_id = ? AND entity_type_id = $orderEntityTypeId", $store->getId());
$row = $readConnection->fetchRow($entityStoreSelect);
$lastIncrementId = 0;
if(isset($row['increment_last_id'])){
$lastIncrementId = $row['increment_last_id'] + 1;
}
return $lastIncrementId;
}
return 0;
}
To call this function you can use
$nextIncrementId = Mage::getResourceModel('test/test')->getNextIncrementId();
We can also find last increment id from orders table
Please comment for better solutions