# Bar Chart (Notchset): prompt.md (v1.0.0)

- id: `bar-chart` · version 1.0.0 · component · pro (Pro)
- category: Charts
- build: Base UI (one set of files; its dependencies follow the build)
- install (this build): `npx shadcn@latest add @beautiful-ui-pro/bar-chart`
- npm dependencies: none
- registry dependencies: utils, https://beautiful-ui.dev/r/notchset-foundation.json
- docs: https://beautiful-ui.dev/components/bar-chart
- The install command carries everything this item needs (files, CSS, tokens, npm and registry dependencies). Prefer it to copying source by hand.

Square bars that grow from an ink baseline, outlined bars for weekends, a right-hand axis with ticks, two-row labels, a gliding dashed average, and a hover that dims the rest and lifts the value.

## Build it
- Stack: React 19 (`ref` is a plain prop), TypeScript, Tailwind CSS v4 utilities, a shadcn-initialised project with the `@/*` alias.
- Packages: none beyond React.
- Files: `components/ui/notchset/bar-chart.tsx`; shared code: `lib/beautiful-ui/notchset/instrument.tsx`, `lib/beautiful-ui/notchset/root.ts`, `lib/beautiful-ui/notchset/calendar.tsx`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `notchset-foundation`.
- Builds: one set of files for both, but its dependencies come in Base UI and Radix builds. Install the one that matches the project (see Install): a free item's bare URL installs the Base UI build of it and its dependencies.
- Exports to keep: `BarChart`, and every exported type.
- CSS: the install adds the notchset foundation (tokens, keyframes, motion levels) to your global stylesheet once. Nothing to import by hand.
- Re-running `add` (or `--overwrite`) re-applies those rules: put overrides in your own CSS, never in the installed rules.
- Tokens: retheme with the `--notchset-*` custom properties (`--notchset-check`, `--notchset-control-edge`, `--notchset-draw-from`, `--notchset-ease-bloom`, `--notchset-ease-travel`, `--notchset-fade`, `--notchset-focus-color`, `--notchset-focus-inset`, `--notchset-life-from`, `--notchset-life-ms`, `--notchset-node-blink`, `--notchset-node-bloom`, `--notchset-node-delay`, `--notchset-plate-color`, `--notchset-rise-from`, `--notchset-rule`, `--notchset-scroll`, `--notchset-signal`, `--notchset-sweep-to`). Never add Tailwind colour classes inside the component.

```tsx
import { BarChart, type BarDatum } from "@/components/ui/notchset/bar-chart";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `BarChart` | `bar-chart` | The plot. |

Style a part with `[data-slot="<slot>"]` selectors or its `className`; keep the attributes when editing.

## Sound
- Keep every `data-slot` and `data-sound` attribute: the sound layer reads them.
- Installing this item adds no audio. Nothing plays until the app mounts `SoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/notchset-sound.json`, import from `@/components/ui/notchset/sound-provider`); `useSound()` gives `muted` and `setMuted` for a mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/notchset/bar-chart.tsx` as the reference implementation before changing or recreating anything, and match it: sizes, colours per theme, motion timings, copy and behaviour.
- If you deviate (a prop you can't honour, a style you changed, a dependency you swapped), say so in your reply, part by part.
- Keep the accessibility contract, the keyboard map and the motion levels listed below.

## Use it when
- bar chart, column chart, daily volume, runs per day, histogram, dashboard chart, Notchset
- A count per day, week or category, especially recent days

### Not when
- Long continuous series: use Brush Chart

## Mistakes
- Keep yMax steady across ranges so heights compare

## Usage

```tsx
"use client";

import * as React from "react";
import { BarChart, type BarDatum } from "@/components/ui/notchset/bar-chart";

const days: BarDatum[] = [
  { label: "MON", value: 31200 },
  { label: "TUE", value: 33800 },
  { label: "WED", value: 29500 },
  { label: "THU", value: 35100 },
  { label: "FRI", value: 32400 },
  { label: "SAT", value: 18100, outline: true },
  { label: "SUN", value: 16900, outline: true },
];

export function RunsPerDay() {
  const [day, setDay] = React.useState<number | null>(null);
  return (
    <div className="grid gap-2">
      <span className="font-mono text-xs">{day == null ? "HOVER A DAY" : `${days[day]!.label} · ${days[day]!.value.toLocaleString()} RUNS`}</span>
      <BarChart data={days} yMax={40000} unit="RUNS" active={day} onActiveChange={setDay} />
    </div>
  );
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `data` | `{ value, label?, sub?, outline? }[]` |  | Bars; label and sub make a two-row tick. |
| `yMax / yTicks` | `number` |  | The scale (4 gridlines). |
| `unit` | `string` |  | The axis caption. |
| `average` | `boolean` |  | The dashed average line (on). |
| `active / onActiveChange` | `number \| null` |  | The hovered bar, for your header. |

Full docs: https://beautiful-ui.dev/components/bar-chart

## Customising
- Colours: the component reads your shadcn tokens (`--background`, `--foreground`, `--border` …), refined by the `--notchset-*` tokens. The signal colour is `--notchset-signal` (it falls back to `--destructive`). Set tokens on `:root`, or on any container to retheme one area.
- Dark mode follows the `.dark` class on an ancestor (the shadcn and next-themes convention).
- Update later by re-running the install with `--overwrite` (review the diff if you edited it). Changelog: https://beautiful-ui.dev/r/changelog.json

## Keyboard

| Keys | Action |
|---|---|
| — | Pointer hover only; put the values in text nearby |

## Performance

- One SVG; CSS transitions.

## Responsive

- Scales with its container (viewBox).

## Motion inventory

| Interaction | What moves |
|---|---|
| Data | Bars grow from the baseline (640ms), 45ms apart (12ms past 10 bars) |
| Average | Glides to the new mean (520ms) |
| Hover | Others dim; the value glides above the bar (220ms) |

## Accessibility contract (preserve when editing)
- An image labelled by you; pair it with the numbers in text (the header)

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/bar-chart
```

Pro item: needs the `@beautiful-ui-pro` registry in `components.json` and `BEAUTIFUL_UI_TOKEN` in `.env.local` (https://beautiful-ui.dev/account). Setup: https://beautiful-ui.dev/docs/pro. Your components.json `style` picks the build: radix-*, new-york and default get Radix, base-* gets Base UI.

## Credits
- Built on shadcn/ui (https://ui.shadcn.com)

The notchset foundation (the tokens listed above, keyframes and motion levels) installs once with the first component; its CSS is public at https://beautiful-ui.dev/r/notchset-foundation.json.