Back in the ArcInfo workstation days there was a concept know as Reference Columns (I think). The idea is this. A user calls with a serivce complaint. A a feature and a date is populated indicating when the feature is created. Another column keeps track of the complaint status... open/closed. As long as that complaint is open a third field is created and a framework is inplace to note that state is open and the current date. The fiels is then populated with the number of days open which is based on the created date and the current date.
Another example. Users creates a polygon or line etc, and the refecence framework allows me to auto calculate on the fly representing the area of the polygon in Acres or the lenth of the line in miles or feet. So the framework would need to have the logic to allow me to create a calculation, and pick 1 or more fields that need to be involved.
Conceptually this is exactly like a Database trigger but implemented in the ArcGIS Platform. Ideally this would workin in a geodatabase or on a hosted feature service in ArcGIS Online or Portal for ArcGIS.
This would be incredibly useful to mobile field collectors, Operations Dashboards, and web applications
