demo D216

Heatmap in htmx

A measure at the crossing of two categories

type: 'heatmap', x, series, y

This draws a heatmap of a measure at the crossing of two categories, with a colour-scale legend showing the low and high of the range. It shows where the highs and lows sit across a grid of combinations, so a pattern across two dimensions reads as colour rather than a table of figures. Switch the ramp scale above the chart between linear, log and quantile and watch the legend redraw to match.

Building…

Loading a live grid…

This is the htmx version. A server-rendered table is upgraded in place, so the page is readable before any script runs and gains the full grid when the module loads, which suits a progressively enhanced app.

The configuration

<link rel="stylesheet" href="https://cdn.latticegrid.dev/lattice-grid@1.107.0/lattice-grid.min.css">

<div id="chart" style="height: 340px"></div>
<!-- A real, server-rendered table: readable with JavaScript off. data-field on
     each header names the column that cell becomes, and data-id on each row is
     the key the grid carries it under. -->
<table id="chart-types-heatmap-table" data-lattice-grid>
  <thead>
    <tr>
      <th data-field="circuit">Circuit</th>
      <th data-field="region">Region</th>
      <th data-field="status">Status</th>
      <th data-field="bandwidth">Bandwidth</th>
      <th data-field="charge">Monthly charge</th>
    </tr>
  </thead>
  <tbody>
    <tr data-id="0"><td>DFB-EDI-100000</td><td>Edinburgh</td><td>live</td><td>100</td><td>94.88</td></tr>
    <tr data-id="1"><td>MPL-BIR-100001</td><td>Birmingham</td><td>provisioning</td><td>10000</td><td>4324.6</td></tr>
    <tr data-id="2"><td>DFB-LON-100002</td><td>London</td><td>live</td><td>2000</td><td>1031.02</td></tr>
    <!-- the rest of the rows, rendered by your server -->
  </tbody>
</table>

<script type="module">
  import { hydrateTable } from 'https://cdn.latticegrid.dev/lattice-grid@1.107.0/modules/htmx.esm.min.js';
  import { createChart } from 'https://cdn.latticegrid.dev/lattice-grid@1.107.0/modules/charts.esm.min.js';

  // The markup carries the rows; a server-rendered table's column types are
  // declared in the config hydrateTable takes. The grid replaces the table
  // where it stood.
  const grid = hydrateTable(document.getElementById('chart-types-heatmap-table'), {
    columns: [
      { field: 'circuit', title: 'Circuit', layout: { width: 180 } },
      { field: 'region', title: 'Region', filter: { type: 'set' } },
      { field: 'status', title: 'Status', filter: { type: 'set' } },
      { field: 'bandwidth', title: 'Bandwidth', type: 'number' },
      { field: 'charge', title: 'Monthly charge', type: 'number',
        format: { style: 'currency', currency: 'GBP' }, total: 'sum' },
    ],
  });

  // Heatmap takes two categories, x and series, and a measure, y, at each cell.
  createChart({ grid, container: '#chart', type: 'heatmap',
    x: 'region', series: 'status', y: 'charge', diverging: true });
</script>