Filter
A filter is a control or rule that shows only items matching chosen conditions. It doesn't change the source data.
A real example
A task list shows unfinished work due this week and assigned to the current user. The active filters stay visible.
Main parts
- 01Visible label
- 02Interaction target
- 03Current state
- 04Keyboard behavior
Use it when
Use it when people often need useful smaller sets from a large collection.
Do not use it when
Never hide default filters. Let people undo filtering and remove filters clearly.
Name used in code
query params / predicate Before you ship
Give assistive tools the control’s name (accessible name), purpose (role), value, and state. Check keyboard use, visible focus, target size, disabled and busy states, feedback, and recovery.
Outcome: Use Filter to solve this user need without losing the current context. User context: A task list shows unfinished work due this week and assigned to the current user. The active filters stay visible. Recommended pattern: Filter. Why it fits: Use it when people often need useful smaller sets from a large collection. Do not use it when: Never hide default filters. Let people undo filtering and remove filters clearly. Product requirements: Define the default, loading, empty, error, success, and recovery states. Keep user input. Give clear feedback after every action. Accessibility and resilience: Use semantic HTML, full keyboard access, and visible focus. Make the layout work when zoomed and support reduced motion. Follow the project’s current rules. Do not add a new UI library unless the project already uses it. Acceptance criteria: The main task works with keyboard only and at 320px width. Focus and status changes are announced. Check loading, failure, retry, cancel, and reduced-motion paths. Evidence and limits (evidence boundary): No single official standard controls the whole term. Its meaning may change across teams, platforms, or frameworks. Unknowns to confirm: Product wording, data source, analytics events, supported devices and languages, and platform limits.
Check this request
Review the current use of Filter. Definition: A filter is a control or rule that shows only items matching chosen conditions. It doesn't change the source data. Release checks: Give assistive tools the control’s name (accessible name), purpose (role), value, and state. Check keyboard use, visible focus, target size, disabled and busy states, feedback, and recovery. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.