JL Kruger
5422131782
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46 lines
1.2 KiB
Markdown
46 lines
1.2 KiB
Markdown
---
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title: Put Interaction Logic in Event Handlers
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impact: MEDIUM
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impactDescription: avoids effect re-runs and duplicate side effects
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tags: rerender, useEffect, events, side-effects, dependencies
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---
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## Put Interaction Logic in Event Handlers
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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.
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**Incorrect (event modeled as state + effect):**
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```tsx
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function Form() {
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const [submitted, setSubmitted] = useState(false)
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const theme = useContext(ThemeContext)
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useEffect(() => {
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if (submitted) {
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post('/api/register')
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showToast('Registered', theme)
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}
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}, [submitted, theme])
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return <button onClick={() => setSubmitted(true)}>Submit</button>
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}
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```
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**Correct (do it in the handler):**
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```tsx
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function Form() {
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const theme = useContext(ThemeContext)
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function handleSubmit() {
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post('/api/register')
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showToast('Registered', theme)
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}
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return <button onClick={handleSubmit}>Submit</button>
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}
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```
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Reference: [Should this code move to an event handler?](https://react.dev/learn/removing-effect-dependencies#should-this-code-move-to-an-event-handler)
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