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Documentation for Layer Cake v10, before Svelte 5 runes. Current docs at layercake.graphics

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Stacked bar

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Stacked bar chart using D3's stack function. Because this creates a nested data structure, we use Layer Cake's flatten function to pass a flat list to the flatData prop. See the client-side example for the same chart with Layer Cake's stack helper.

This is the server-side rendered version. ssr and percentRange on <LayerCake> put the scales in percentages, so the chart renders before the browser measures it. The axes are HTML components and the marks sit in a <ScaledSvg> that stretches to fit its box.

  • +page.svelte
  • ./_components/BarStacked.svelte
  • ./_components/AxisX.percent-range.html.svelte
  • ./_components/AxisY.percent-range.html.svelte
  • ./_data/fruitOrdinal.csv
<script>
  import { LayerCake, ScaledSvg, Html, flatten } from 'layercake';
  import { stack } from 'd3-shape';

  import { scaleBand, scaleOrdinal } from 'd3-scale';
  import { format } from 'd3-format';

  import BarStacked from './_components/BarStacked.svelte';
  import AxisX from './_components/AxisX.percent-range.html.svelte';
  import AxisY from './_components/AxisY.percent-range.html.svelte';

  // The CSV rows are parsed, and their numbers typed, by @rollup/plugin-dsv. See vite.config.js
  import data from './_data/fruitOrdinal.csv';

  // Each stacked point is a [start, end] pair, so the x accessor is those two indexes
  const xKey = [0, 1];
  const yKey = 'year';
  const cKey = 'key';

  const seriesNames = Object.keys(data[0]).filter(d => d !== yKey);
  const seriesColors = ['#00bbff', '#8bcef6', '#c4e2ed', '#f7f6e3'];

  const formatLabelX = format('~s');

  // d3's stack turns the wide rows into one series per key, each a list of [start, end] pairs
  const stackedData = stack().keys(seriesNames)(data);
</script>

<div class="chart-container">
  <LayerCake
    ssr
    percentRange
    padding={{ bottom: 20, left: 35 }}
    x={xKey}
    y={d => d.data[yKey]}
    c={cKey}
    yScale={scaleBand().paddingInner(0.05)}
    cScale={scaleOrdinal()}
    yDomainSort={true}
    cDomain={seriesNames}
    cRange={seriesColors}
    flatData={flatten(stackedData)}
    data={stackedData}
  >
    <Html>
      <AxisX showBaseline snapLabels format={formatLabelX} />
      <AxisY gridlines={false} />
    </Html>
    <ScaledSvg>
      <BarStacked />
    </ScaledSvg>
  </LayerCake>
</div>

<style>
  /* Give the wrapper a width and height. LayerCake fills it. */
  .chart-container {
    width: 100%;
    height: 250px;
  }
</style>