# 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.

- Skill: `tools-only/put-interaction-logic-in-event-handlers` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add tools-only/put-interaction-logic-in-event-handlers`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tools-only/put-interaction-logic-in-event-handlers/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tools-only (https://skillmd.com/u/tools-only)
- Updated: 2026-09-29
- Page: https://skillmd.com/skills/tools-only/put-interaction-logic-in-event-handlers

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## 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):**

```tsx
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):**

```tsx
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?](https://react.dev/learn/removing-effect-dependencies#should-this-code-move-to-an-event-handler)