Examples

1props { user, unreadCount, messages }: { user: { name: string; id: string; isAdmin: boolean }; unreadCount: number; messages: { id: string; text: string }[] }2.card3  .header4    h1 Welcome, #{user.name}5  .body6    if user.isAdmin7      AdminPanel(userId={user.id})8    else9      p You have #{unreadCount} new messages10    ul.messages11      each message, i in messages12        li.message(key={message.id}) #{message.text}

1export default function Card({2	user,3	unreadCount,4	messages,5}: {6	user: { name: string; id: string; isAdmin: boolean };7	unreadCount: number;8	messages: { id: string; text: string }[];9}) @{10	<div className="card">11		<div className="header">12			<h1>Welcome, {user.name}</h1>13		</div>14		<div className="body">15			@if (user.isAdmin) {16				<AdminPanel userId={user.id} />17			} @else {18				<p>You have {unreadCount} new messages</p>19			}20			<ul className="messages">21				@for (const message of messages; index i; key message.id) {22					<li className="message">{message.text}</li>23				}24			</ul>25		</div>26	</div>27}

1import { useEffect, useMemo, useState } from "octane";2props { initialCount, step, onCountChange }: { initialCount: number; step: number; onCountChange: (count: number) => void }3setup const [count, setCount] = useState(initialCount);4setup const doubled = useMemo(() => count * 2);5setup useEffect(() => onCountChange(count));6 7section.counter(aria-live="polite")8  h2 Hook counter9  p Current: #{count}10  p Doubled: #{doubled}11  .actions12    button(type="button" onClick={() => setCount(count - step)}) Decrease13    button(type="button" onClick={() => setCount(count + step)}) Increase

1import { useEffect, useMemo, useState } from "octane";2 3export default function Counter({4	initialCount,5	step,6	onCountChange,7}: {8	initialCount: number;9	step: number;10	onCountChange: (count: number) => void;11}) @{12	const [count, setCount] = useState(initialCount);13	const doubled = useMemo(() => count * 2);14	useEffect(() => onCountChange(count));15 16	<section className="counter" aria-live="polite">17		<h2>Hook counter</h2>18		<p>Current: {count}</p>19		<p>Doubled: {doubled}</p>20		<div className="actions">21			<button type="button" onClick={() => setCount(count - step)}>Decrease</button>22			<button type="button" onClick={() => setCount(count + step)}>Increase</button>23		</div>24	</section>25}

1props { products, selectedId, onSelect }: { products: { id: string; name: string; price: number; featured: boolean }[]; selectedId: string | null; onSelect: (id: string) => void }2 3section#catalog.catalog(aria-label="Product catalog")4  h2 Products5  ul.product-grid6    each product, index in products key product.id7      li.product-card(className={product.id === selectedId ? "selected" : ""} data-index={index})8        if product.featured9          span.badge Featured10        h3 #{product.name}11        p.price $#{product.price.toFixed(2)}12        button(type="button" formNoValidate disabled={product.id === selectedId} onClick={() => onSelect(product.id)}) Select13    empty14      li.empty-state No products available.

1export default function Catalog({2	products,3	selectedId,4	onSelect,5}: {6	products: { id: string; name: string; price: number; featured: boolean }[];7	selectedId: string | null;8	onSelect: (id: string) => void;9}) @{10	<section id="catalog" className="catalog" aria-label="Product catalog">11		<h2>Products</h2>12		<ul className="product-grid">13			@for (const product of products; index index; key product.id) {14				<li className={[product.id === selectedId ? "selected" : "", "product-card"].filter(Boolean).join(" ")} data-index={index}>15					@if (product.featured) {16						<span className="badge">Featured</span>17					}18					<h3>{product.name}</h3>19					<p className="price">${product.price.toFixed(2)}</p>20					<button type="button" formNoValidate disabled={product.id === selectedId} onClick={() => onSelect(product.id)}>Select</button>21				</li>22			} @empty {23				<li className="empty-state">No products available.</li>24			}25		</ul>26	</section>27}

1module interface StylingProps { title: string; cardProps: Record<string, unknown> }2props { title, cardProps }: StylingProps3 4fragment5  article.card({...cardProps})6    h2 #{title}7    p Scoped styling follows this component.8  style9    .card {10      padding: 1rem;11    }12 13    .card h2 {14      color: rebeccapurple;15    }16 17    :global(body) {18      margin: 0;19    }

1interface StylingProps { title: string; cardProps: Record<string, unknown> }2 3export default function Styling({ title, cardProps }: StylingProps) @{4	<>5		<article className="card" {...cardProps}>6			<h2>{title}</h2>7			<p>Scoped styling follows this component.</p>8		</article>9		<style>10			.card {11			  padding: 1rem;12			}13 14			.card h2 {15			  color: rebeccapurple;16			}17 18			:global(body) {19			  margin: 0;20			}21		</style>22	</>23}

1import { createContext, use, useContext } from "octane";2module3  type ThemeName = "light" | "dark";4  interface ProviderProps {5    theme: ThemeName;6    children: unknown;7  }8 9  const Theme = createContext<ThemeName>("light");10 11component ThemeLabel12  setup const theme = use(Theme);13  p.theme-label #{"Current theme: " + theme}14 15component ThemeSwatch16  setup const theme = useContext(Theme);17  span(aria-label={"Theme swatch: " + theme} data-theme={theme})18props { theme, children }: ProviderProps19 20Theme.Provider(value={theme})21  section.theme-shell(data-theme={theme})22    ThemeLabel23    ThemeSwatch24    | #{children}

1import { createContext, use, useContext } from "octane";2type ThemeName = "light" | "dark";3interface ProviderProps {4	 theme: ThemeName;5	 children: unknown;6}7 8const Theme = createContext<ThemeName>("light");9 10function ThemeLabel() @{11	const theme = use(Theme);12 13	<p className="theme-label">{"Current theme: " + theme}</p>14}15 16function ThemeSwatch() @{17	const theme = useContext(Theme);18 19	<span aria-label={"Theme swatch: " + theme} data-theme={theme} />20}21 22export default function Provider({ theme, children }: ProviderProps) @{23	<Theme.Provider value={theme}>24		<section className="theme-shell" data-theme={theme}>25			<ThemeLabel />26			<ThemeSwatch />27			{children}28		</section>29	</Theme.Provider>30}

1props { Profile, data }: { Profile: (props: { data: Promise<unknown> }) => unknown; data: Promise<unknown> }2 3section.profile-boundary4  try5    Profile(data={data})6  pending7    p(role="status") Loading profile…8  catch error, reset9    .error(role="alert")10      p Could not load profile: #{error instanceof Error ? error.message : String(error)}11      button(type="button" onClick={reset}) Try again

1export default function Boundary({2	Profile,3	data,4}: {5	Profile: (props: { data: Promise<unknown> }) => unknown;6	data: Promise<unknown>;7}) @{8	<section className="profile-boundary">9		@try {10			<Profile data={data} />11		} @pending {12			<p role="status">Loading profile…</p>13		} @catch (error, reset) {14			<div className="error" role="alert">15				<p>Could not load profile: {error instanceof Error ? error.message : String(error)}</p>16				<button type="button" onClick={reset}>Try again</button>17			</div>18		}19	</section>20}

1props { heading, count }: { heading: string; count: number }2 3// Multiple roots compile to a native TSRX fragment.4h1 #{heading}5| This view intentionally has multiple roots.6p.notice You have #{count} pending items.7| Symbols stay safe: < > { } &.

1export default function Fragment({2	heading,3	count,4}: {5	heading: string;6	count: number;7}) @{8	<>9		<h1>{heading}</h1>10		This view intentionally has multiple roots.11		<p className="notice">You have {count} pending items.</p>12		Symbols stay safe: &lt; &gt; &#123; &#125; &amp;.13	</>14}

1props { state }: { state: "idle" | "loading" | "ready" | "error" }2 3section.status-card(aria-live="polite")4  switch state5    case "idle"6      p Choose an action.7    case "loading"8      p(role="status") Loading…9    case "ready"10      p Ready.11    default12      p(role="alert") Something went wrong.

1export default function Variant({2	state,3}: {4	state: "idle" | "loading" | "ready" | "error";5}) @{6	<section className="status-card" aria-live="polite">7		@switch (state) {8			@case "idle": {9				<p>Choose an action.</p>10			}11			@case "loading": {12				<p role="status">Loading…</p>13			}14			@case "ready": {15				<p>Ready.</p>16			}17			@default: {18				<p role="alert">Something went wrong.</p>19			}20		}21	</section>22}