What Business Rules Do
Show/hide fields, set required/optional, default values, validation messages. Declarative. No code. Apply to forms, tables, or both.
When They Fit
Field-level visibility, simple validations, default values based on other fields. The 80% case of form logic is better served here than in JavaScript.
When They Don’t
Async operations, external calls, complex branching, multi-record logic. Reach for Power Fx (canvas apps), Power Automate (async), or plug-ins (sync server-side).
Performance
Business rules run client-side on form load and on field change. Keep rules narrow; many rules on a heavy form create lag.
Governance
Document each rule’s purpose. The form-level rule and table-level rule distinction matters — table-level runs on API operations too. Don’t mix intent.