shadcn/ui for Inertia Rails

shadcn/ui patterns adapted for Inertia.js + Rails + React. NOT Next.js.

Before using a shadcn example, ask:

Does it use
react-hook-form
+
zod
? → Replace with Inertia
```
<Form>
```
+
```
name
```
attributes. Inertia handles CSRF, errors, redirects, processing state — react-hook-form would fight all of this.
Does it use
'use client'
? → Remove it. Inertia has no RSC — all components are client components.

Does it use
next/link
,
next/head
,
useRouter()
? → Replace with Inertia

<Link>

<Head>

router

Key Differences from Next.js Defaults

shadcn default (Next.js)	Inertia equivalent
`'use client'` directive	Remove — not needed (no RSC)
`react-hook-form` + `zod`	Inertia `<Form>` component
`FormField` , `FormItem` , `FormMessage`	Plain `<Input name="...">` + `errors.field`
`next-themes`	CSS class strategy + `@custom-variant`
`useRouter()` (Next)	`router` from `@inertiajs/react`
`next/link`	`<Link>` from `@inertiajs/react`
`next/head`	`<Head>` from `@inertiajs/react`

NEVER use shadcn's
FormField
,
FormItem
,
FormLabel
,
FormMessage
components — they depend on react-hook-form's

useFormContext

internally and will crash without it. Use plain shadcn

Input

Label

Select

with

name

attributes inside Inertia

<Form>

, and render errors from the render function's

errors

object (see examples below).

Setup

npx shadcn@latest init

. add

@/

resolve aliases to

tsconfig.json

if not present, Do NOT add
@/
resolve aliases to
vite.config.ts
—

vite-plugin-ruby

already provides them.

shadcn Inputs in Inertia

<Form>

Use plain shadcn

Input

Label

Button

with

name

attributes inside Inertia

<Form>

. See

inertia-rails-forms

skill for full

<Form>

API — this section covers shadcn-specific adaptation only.

The key pattern: Replace shadcn's

FormField

FormItem

FormMessage

with plain components + manual error display:

tsx

// shadcn error display pattern (replaces FormMessage):
<Label htmlFor="name">Name</Label>
<Input id="name" name="name" />
{errors.name && <p className="text-sm text-destructive">{errors.name}</p>}

<Select>
requires
name
prop for Inertia

<Form>

integration — shadcn examples omit it because react-hook-form manages values differently:

tsx

<Select name="role" defaultValue="member">
  <SelectTrigger><SelectValue placeholder="Select role" /></SelectTrigger>
  <SelectContent>
    <SelectItem value="admin">Admin</SelectItem>
    <SelectItem value="member">Member</SelectItem>
  </SelectContent>
</Select>

Dialog with Inertia Navigation

tsx

import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/ui/dialog'
import { router } from '@inertiajs/react'

function UserDialog({ open, user }: { open: boolean; user: User }) {
  return (
    <Dialog
      open={open}
      onOpenChange={(isOpen) => {
        if (!isOpen) {
          router.replaceProp('show_dialog', false)
        }
      }}
    >
      <DialogContent>
        <DialogHeader>
          <DialogTitle>{user.name}</DialogTitle>
        </DialogHeader>
        {/* content */}
      </DialogContent>
    </Dialog>
  )
}

Table with Server-Side Sorting

shadcn

<Table>

renders normally. The Inertia-specific part is sorting via

router.get

tsx

const handleSort = (column: string) => {
  router.get('/users', { sort: column }, { preserveState: true })
}

<TableHead onClick={() => handleSort('name')} className="cursor-pointer">
  Name {sort === 'name' && '↑'}
</TableHead>

Use

<Link>

(not

<a>

) for row links to preserve SPA navigation.

Toast with Flash Messages

Flash config (

flash_keys

) is in

inertia-rails-controllers

. Flash access (

usePage().flash

) is in

inertia-rails-pages

. This section covers toast UI wiring only.

MANDATORY — READ ENTIRE FILE when implementing flash-based toasts with Sonner:

references/flash-toast.md

(~80 lines) — full

useFlash

hook and Sonner toast provider. Do NOT load if only reading flash values without toast UI.

Key gotcha:

flash_keys

in the Rails initializer MUST match your

FlashData

TypeScript type — do NOT use

success

error

unless you also update both.

Dark Mode (No next-themes)

npx shadcn@latest init

generates CSS variables for light/dark and

@custom-variant dark (&:is(.dark *));

in your CSS (Tailwind v4). No extra setup needed for the variables themselves.

CRITICAL — prevent flash of wrong theme (FOUC): Next.js handles this automatically; Inertia does NOT. Add an inline script in

<head>

(before React hydrates) and call

initializeTheme()

in your Inertia entrypoint:

erb

<%# app/views/layouts/application.html.erb — in <head>, before any stylesheets %>
<script>
  document.documentElement.classList.toggle(
    "dark",
    localStorage.appearance === "dark" ||
      (!("appearance" in localStorage) && window.matchMedia("(prefers-color-scheme: dark)").matches),
  );
</script>

tsx

// app/frontend/entrypoints/inertia.tsx
import { initializeTheme } from '@/hooks/use-appearance'
initializeTheme() // must run before createInertiaApp

Use a

useAppearance

hook (light/dark/system modes, localStorage persistence,

matchMedia

listener) instead of

next-themes

. Toggle via

.dark

class on

<html>

— no provider needed.

Troubleshooting

Symptom	Cause	Fix
`FormField` / `FormMessage` crash	Using shadcn form components that depend on react-hook-form	Replace with plain `Input` / `Label` + `errors.field` display
`Select` value not submitted	Missing `name` prop	Add `name="field"` to `<Select>` — shadcn examples omit it
Dialog closes unexpectedly	Missing or wrong `onOpenChange` handler	Use `onOpenChange={(open) => { if (!open) closeHandler() }}`
Flash of wrong theme (FOUC)	Missing inline `<script>` in `<head>`	Add dark mode script before stylesheets (see Dark Mode section)

Related Skills

Form component →
```
inertia-rails-forms
```
(
```
<Form>
```
render function, useForm)
Flash config →
```
inertia-rails-controllers
```
(flash_keys initializer)
Flash access →
```
inertia-rails-pages
```
(usePage().flash)
URL-driven dialogs →
```
inertia-rails-pages
```
(router.get pattern)

References

Load

references/components.md

(~300 lines) when building shadcn components beyond those shown above (Accordion, Sheet, Tabs, DropdownMenu, AlertDialog with Inertia patterns).

Do NOT load

components.md

for basic Form, Select, Dialog, or Table usage — the examples above are sufficient.

shadcn-inertia

NPX Install

Tags

SKILL.md Content