Webtools 2007 cart page

Question

Hey All,
I am trying to add some additional shipping expenses using the NPOrderExpense object during my clients check out process. I can add the OrderExpenses with no problem and they show up in the database after the shipping page. But if I go back to the cart page at any point during my flow ecommerce deletes all of my Shipping expenses and just adds its own back into the database.
Any ideas why it is doing that?

Answer 1

Maybe I'm just confused or just confusing things....
I should probably not used the word "override".
You can not override the NPOrder.Calculate() that runs on cart.  You need to let the cart re calculate and then run your calculation to correct it.
At this point I have assumed you have written all of the code to get the order/expenses/payments the way you want them (when you did the verify page).
Am I right here?
The cart will run the Calculate() and override your work, so you will need to re-run your calculation code to reset the order back to your calculations.
You can do this either on the cart.aspx by adding a prerender event to the aspx:
<script>
protected override void OnPreRender(EventArgs e) {
//  Enter your custom calculations here
</script>
or to your plugin--if you have created one for this.
At this point, the UI data has been set, so you will probably need to update any totals that are incorrect.
OK?