Custom field rules: fill in a field when another one changes

A custom field can react to the other fields of the same record: when a box is ticked, a list takes a value or a field is filled in, it receives today's date, a fixed value, or clears itself. The rule plays directly in the form, as you change the trigger field, and the value it sets stays editable before you save.

Example: on a job, ticking "Sourcing request" writes today's date and time into "Request date".

Setting up a rule

1. Open the custom fields customizing of the record (see Create a custom field), then the window of the field to fill in: here "Request date".
2. Expand the Automatic fill-in section at the bottom of the window, then in Rules add a row: If, the trigger field ("Sourcing request"), then the operator ("not empty"). Further rows chain with And if or Or.
3. In Then, pick the action: Fill in today's date (Date and Date & Time fields), Fill in the value (the value to set; for a list, the code of the value), or Clear the field.
4. Save. The section shows how many rules the field has. The rule applies on the record and in the creation form.

Good to know

• On the record, hovering the field label recalls its rule ("Fill in today's date: If « Sourcing request » not empty").
• The rule plays when a trigger field changes, never when the record opens: an older record is not filled in retroactively.
• It plays in the form only: an import, a bulk change or an API update do not apply it.
• A date field used as a trigger is only tested as "empty" or "not empty".
• Computed or composite fields (table, formula, automatic numbering, "based on", lists with control table, stars, text editor, files, people) carry no rule.
• Unticking the box does not remove the date: a rule sets a value, it does not undo it. Add a "Clear the field" rule if needed.