There really is only one sensible way to populate eXtender with data, and that is using SmartConnect. This is the same answer for both Microsoft Dynamics GP Extender or Extender Enterprise.
Natively both versions of Extender contain a simple txt file import that works just like the table import in standard GP. There is no data validation with this method and the import requires a user to define the field links and run the import manually. It works well for one off imports. For anything more complex I would always recommend SmartConnect.
I have had a number of requests form people saying “we recently saw some demos where data was imported into eXtender, how is that done?”. The answer is, eOne developed a set of eConnect nodes that support all eXtender objects inluding windows, detail windows, forms and detail forms. These nodes are available out of the box to anyone that purchases SmartConnect. When you install SmartConnect the eXtender nodes are installed automatically for you and are available for immediate mapping. You can map source data to eXtender fields just like they were any other field in GP, and SmartConnect takes care of the rest.
So whether you are importing 2 extra fields to an eXtender window, bringing in 10,000 records into an eXtender form or populting all your fixed asset records and 4 associated eXtender windows at the same time – SmartConnect is your easy answer. So avoid those complex eXtender tables completely – use SmartConnect to get the data in and then use eXtender views and SmartList Builder’s eXtender resources to get the data out. It does not get easier than that.