Xero

The scheduler calls the following functions, in this order:

getItems
Gets default cost price of all items in Xero

getOrdersForXero
Get all orders from IXO that haven't been acknowledged already, excluding draft, abandoned, cancelled or quotes.
Creates the customer as a contact in Xero if it doesn't already exist.
Ensures all sold products exist in Xero. Adds them if not.
Posts an invoice to Xero as "draft" status

getReturnsForXero
Gets all returned items that haven't been acknowledged already.
Ensure the customer exists in Xero. Adds one if not.
Creates Credit Note in Xero as "draft" status

getPurchaseOrdersForXero
Gets all submitted purchase orders that haven't been acknowledged.
Ensures supplier exists as a contact. Adds one if not.
Ensures all products exist as items in Xero.
Creates a Purchase Order in Xero.

getUnpaidInvoices
Gets a list of unpaid invoices from Xero.
Compares payments in IXO against the Sales Order ID.
Creates a payment in Xero if one exists.

getUnpaidCreditNotes
Gets a list of unpaid credit notes from Xero.
Compares refunds in IXO against the Sales Order ID.
Creates a payment in Xero if one exists.

Configs

All Sales Order invoices can either be created as draft invoices, or as authorised. 

There is a config that will change this. If created as draft invoices, they can be automatically updates to 'authorised' once all non cancelled lines on a Sales Order are marked as completed.