"Count" Function Fails to Update for External Data Sources
Re: FMPA 13v2
I am developing a "data separation model" FileMaker solution, where there is a Data file which contains all records, and a UI file which _references_ the Data file as an External Data Source.
In the Data file, there is an Invoices table and an Invoice Items table. The Invoices table defines a field which "Counts" the number of Invoice Items related to it. When viewing Invoice records in the Data file, adding and removing Invoice Items properly updates the "Count of Invoice Items" value.
But, in the UI file, where the layout is displaying Invoice records from the external data source, the "Count of Invoice Items" value is _not_ properly updated when related records are added or removed. The value stays "wrong" until the user clicks in the "Count" field in the UI file -- and then the value suddenly updates.
How to work-around this update bug in FileMaker 13?