Sidebar

A collapsible vertical icon rail. Collapsed, it shows icon-only SidebarItems; open, each item's label appears next to its icon - rendered away from the anchored edge (a right-anchored rail shows labels to the left of the icons). The rail renders as a <nav> landmark and requires an aria-label so multiple navigation regions stay distinguishable.

The open state is purely controlled: pass isOpen and flip it from wherever your layout keeps the menu toggle - usually a hamburger button in the app bar, not inside the rail. Children compose freely: SidebarItems, a sponsor logo, a footer, dividers - anything. Items read the open state and anchor through SidebarContext, so they need no wiring of their own.

Usage

import { Sidebar, SidebarItem } from '@soroush.tech/design-system/Sidebar'

const [isOpen, setIsOpen] = useState(false)

// The toggle lives in your app bar:
<Button aria-label="Expand menu" aria-expanded={isOpen} onClick={() => setIsOpen(!isOpen)}>
  <Icon name="menu" />
</Button>

<Sidebar aria-label="Editor panels" anchor="right" isOpen={isOpen} bg="paper">
  <SidebarItem icon="folder" label="Directory" isSelected onSelect={openDirectory} />
  <SidebarItem icon="terminal" label="Terminal console" onSelect={openTerminal} />
  <Typography variant="caption" mt="auto">v1.1.0</Typography>
</Sidebar>

Panel column

With hasPanel, the rail gains a second column and the selected item's children render there instead of inside its row - an icon rail beside a detail panel. Without it, children render inline in the row as usual, so the mode is opt-in and changes nothing for existing rails.

<Sidebar aria-label="Editor panels" isOpen={isOpen} hasPanel panelWidth="20rem">
  <SidebarItem
    icon="folder"
    label="Directory"
    isSelected={panel === 'directory'}
    onSelect={() => setPanel('directory')}
  >
    <DirectoryTree /> {/* renders in the panel, not in the row */}
  </SidebarItem>
</Sidebar>

Selection stays yours - the rail only decides where the selected item's children go. The selected item ports its children into the panel through Portal, so they stay declared and mounted inside the item: whatever context, state, and handlers they close over resolve against the item's own position in the React tree, and the item can sit at any depth in the rail - inside your own grouping component, a fragment, or a map - with no requirement to be a direct child.

Because the content is ported rather than lifted, it is client-only: Portal renders nothing during server rendering, so a server-rendered panel arrives empty and fills in on hydration. The rail and its items server-render as normal.

• The panel column stays mounted as the port target, but collapses while empty (:empty), so nothing selected - or a selection with no children - leaves no gap. Unnamed while empty too, so an idle panel is not announced as a region.
• It is independent of isOpen, so a collapsed icons-only rail can sit beside an open panel.
• It sits on the rail's inner side, following anchor, and inside the <nav>, so the rail's bg and padding cover it too rather than stopping at the rail's edge.
• The panel is a <section> named by the item's label, and that item becomes a disclosure - aria-expanded, plus aria-controls pointing at the panel while it is shown.

Style or re-tag the column with panelProps - any Flex prop, plus as. It overrides panelWidth and the derived aria-label; the id and ref stay with the rail, which needs them as the port target and the aria-controls anchor.

<Sidebar aria-label="Editor panels" isOpen={isOpen} hasPanel
  panelProps={{ as: 'aside', bg: 'paper', p: 3, borderLeft: 'thin' }}
>