Cancelability
actions.cancelability
Provide a way to instantly cancel a time-consuming operation with no side effects.
Description
Long operations need an escape hatch. Provide a way to cancel at once, and ensure cancelled work leaves no lingering side effects on data or state. Missing cancel, a cancel that is not instant, or a cancel that still applies changes traps people in unwanted work they cannot stop. Use this for multi-second jobs such as uploads, exports, or batch processing; skip it for actions that complete immediately where a cancel control would never be usable in time.
When to use
Long-running work such as uploads, exports, or batch jobs.
Not when
Instant actions that finish before a cancel control would help.
Agent hint
Offer instant cancel on long work and roll back cancelled side effects.
A time-consuming operation can be cancelled at once, with no side effects from the cancelled work.
No cancel, cancel is not instant, or cancel still applies side effects.
Citations
Designing Interfaces 3e ch. Doing Things — Cancelability (Tidwell, Brewer, Valencia)
https://www.oreilly.com/library/view/designing-interfaces-3rd/9781492051954/