I have spent the past couple of weeks building a pretty hefty integration for a client to integrate their Salesforce platform with Xero.

I have now hit an issue as the client wants to specify a String field to be pushed as the reference... This was not an issue with the Invoices as we used the URL field to define what Salesforce record needs to be updated form the API response.

This would be a very good thing for developers to have a specific "External Id" field so clients can do what they like and we have one for ourselves!

Other than that the URL hack worked quite well, but we cannot use this on Purchase Orders as the table does not have a URL field in it!