Displaying an Invoice Created Via the API
If you're using the Payments API to integrate with Spreedly, you'll need to display Spreedly invoices to your customers so they know what it is that they're buying and what they'll be charged for it. For an example of displaying this information, you can look at how Spreedly's hosted UI handles it. Here are a few specific cases you'll want to make sure you cover:
Single Line Item
If Spreedly only returns you a single line item in the invoice, you have the option of just displaying that item rather than bothering with a total.
Multiple Line Items
When Spreedly returns multiple line items, you'll want to make sure you display them all and also a total that shows how they all combine. You shouldn't need to calculate anything - Spreedly provides pre-calculated values for everything you need.
Negative Total
When a subscriber is upgraded they will sometimes end up with a negative total, indicating store credit. Spreedly displays this a separate line and keeps the invoice total at $0, but you could also just display a negative invoice total.