My-Weekly-ToDo-List/.opencode/skills/react-best-practices/rules/rerender-move-effect-to-event.md
mARTin d92a8c7210 feat: add task actions (notes/delete) and refine animation logic
- Added 'onDelete' and 'onNotes' support to TaskItem.
- Implemented hover actions (Delete and Notes icons) for tasks.
- Added Notes Modal for editing task markdown content.
- Simplified navigation animation to remove blank flash (single-phase slide-in).
- Fixed syntax error in updateTask function.
- Updated styles for modal and task actions.
2026-02-01 12:25:53 +01:00

1.2 KiB

title impact impactDescription tags
Put Interaction Logic in Event Handlers MEDIUM avoids effect re-runs and duplicate side effects rerender, useEffect, events, side-effects, dependencies

Put Interaction Logic in Event Handlers

If a side effect is triggered by a specific user action (submit, click, drag), run it in that event handler. Do not model the action as state + effect; it makes effects re-run on unrelated changes and can duplicate the action.

Incorrect (event modeled as state + effect):

function Form() {
  const [submitted, setSubmitted] = useState(false)
  const theme = useContext(ThemeContext)

  useEffect(() => {
    if (submitted) {
      post('/api/register')
      showToast('Registered', theme)
    }
  }, [submitted, theme])

  return <button onClick={() => setSubmitted(true)}>Submit</button>
}

Correct (do it in the handler):

function Form() {
  const theme = useContext(ThemeContext)

  function handleSubmit() {
    post('/api/register')
    showToast('Registered', theme)
  }

  return <button onClick={handleSubmit}>Submit</button>
}

Reference: Should this code move to an event handler?