You actually can do it but it's abit of a hack to get it to work.
- Create a Field_Trigger on a feature to monitor a field, with a placeholder value in the ValueInfo section, something that is very unlikely to appear natively in your data like "11/11/1111". Give the Rule weight a value.
- Note: Dates like "1/1/1111" can cause problems cross systems due to differences in how the system time is set up so stick with 10+ for days and months.
- Create an Expression on the same feature on the same field and make an If statement to look for the placeholder value "11/11/1111" then do what you like with the value, if you want the date use the vbExpression: "Date" to pull the current date. Make sure the rule weight is set to NULL, since rules with a weight of Null are always run last.
Here's an example of the code:
OBJECTID * | Table Name | FIELDNAME | Value Method | Value Info | On Create | On change | On Change (Geometry) | Manual Only | Rule Weight | Comments |
7896 | UndergroundStructureArea | CONSTRUCTIONSTATUS | FIELD_TRIGGER | 15|STATUSCHANGEDATE|11/11/1111 | FALSE | TRUE | FALSE | FALSE | 63 | |
7893 | UndergroundStructureArea | STATUSCHANGEDATE | EXPRESSION | IIF([STATUSCHANGEDATE]="11/11/1111" AND [CONSTRUCTIONSTATUS], Date, Null) | FALSE | TRUE | FALSE | FALSE | <Null> | |