auto-animate

# AutoAnimate - Error Prevention Guide

**Package**: @formkit/auto-animate@0.9.0 (current)
**Frameworks**: React, Vue, Solid, Svelte, Preact
**Last Updated**: 2026-01-21

---

## SSR-Safe Pattern (Critical for Cloudflare Workers/Next.js)

```tsx
// Use client-only import to prevent SSR errors
import { useState, useEffect } from "react";

export function useAutoAnimateSafe<T extends HTMLElement>() {
  const [parent, setParent] = useState<T | null>(null);

  useEffect(() => {
    if (typeof window !== "undefined" && parent) {
      import("@formkit/auto-animate").then(({ default: autoAnimate }) => {
        autoAnimate(parent);
      });
    }
  }, [parent]);

  return [parent, setParent] as const;
}
```

**Why this matters**: Prevents Issue #1 (SSR/Next.js import errors). AutoAnimate uses DOM APIs not available on server.

---

## Known Issues Prevention (15 Documented Errors)

This skill prevents **15** documented issues:

### Issue #1: SSR/Next.js Import Errors
**Error**: "Can't import the named export 'useEffect' from non EcmaScript module"
**Source**: https://github.com/formkit/auto-animate/issues/55
**Why It Happens**: AutoAnimate uses DOM APIs not available on server
**Prevention**: Use dynamic imports (see `templates/vite-ssr-safe.tsx`)

### Issue #2: Conditional Parent Rendering
**Error**: Animations don't work when parent is conditional
**Source**: https://github.com/formkit/auto-animate/issues/8
**Why It Happens**: Ref can't attach to non-existent element
**Prevention**:

**React Pattern**:
```tsx
// ❌ Wrong
{showList && <ul ref={parent}>...</ul>}

// ✅ Correct
<ul ref={parent}>{showList && items.map(...)}</ul>
```

**Vue.js Pattern**:
```vue
<!-- ❌ Wrong - parent conditional -->
<ul v-if="showList" ref="parent">
  <li v-for="item in items" :key="item.id">{{ item.text }}</li>
</ul>

<!-- ✅ Correct - children conditional -->
<ul ref="parent">
  <li v-if="showList" v-for="item in items" :key="item.id">
    {{ item.text }}
  </li>
</ul>
```

**Source**: React