Lazy Children

Nodes marked hasChildren: true load their children on first expand through plotOptions.tree.lazy.load (a Promise; simulated 600 ms latency here). A placeholder card with a spinner shows while loading; a failed load (Services fails once) shows a retry card. childrenLoad / childrenLoadError events.

Chart type: Tree tree
Tier: Premium
Collection: Tree
Render: Live, site theme

View .md Agent setup

LIVE/tree/lazy-children30 of 37 in Tree

Open the chart without page chrome ↗Drawing width at least 1,000 px. Scroll within the chart on smaller screens.

Configuration

Raw Standalone

const options = {
  chart: {
    height: 460,
    toolbar: {
      show: false
    },
    type: "tree",
    events: {
      childrenLoad: (e, ctx, o) => log('childrenLoad ' + o.node.name + ': ' + o.children.length + ' items'),
      childrenLoadError: (e, ctx, o) => log('childrenLoadError ' + o.node.name + ': ' + o.error.message + ' (click the card to retry)')
    }
  },
  series: [
    {
      data: [
        {
          name: "Catalogue",
          children: [
            {
              name: "Hardware",
              hasChildren: true
            },
            {
              name: "Software",
              hasChildren: true
            },
            {
              name: "Services",
              hasChildren: true
            }
          ]
        }
      ]
    }
  ],
  plotOptions: {
    tree: {
      orientation: "left-to-right",
      node: {
        template: "compact"
      },
      lazy: {
        load: (node) => new Promise((res, rej) => setTimeout(() => {
              if (node.name === 'Services' && fails-- > 0) return rej(new Error('timeout'))
              res([1, 2, 3, 4].map((i) => ({ name: node.name + ' ' + i, value: PG.int(10, 90), hasChildren: i === 1 })))
            }, PG.noAnim ? 0 : 600))
      }
    }
  },
  theme: {
    mode: "light",
    preset: "coastal"
  }
}

const chart = new WestCoastCharts(document.querySelector('#chart'), options)
chart.render()

01 · Speccomplete, runnable

import WestCoastCharts from 'west-coast-charts'
import types from 'west-coast-charts/types'
import premium from 'west-coast-charts/premium'

WestCoastCharts.use(types).use(premium)
const WestCoastChartsPremium = premium
WestCoastCharts.setLicenseKey(LICENCE_KEY) // paid production licence; localhost evaluation needs no key

const options = {
  chart: {
    height: 460,
    toolbar: {
      show: false
    },
    type: "tree",
    events: {
      childrenLoad: (e, ctx, o) => log('childrenLoad ' + o.node.name + ': ' + o.children.length + ' items'),
      childrenLoadError: (e, ctx, o) => log('childrenLoadError ' + o.node.name + ': ' + o.error.message + ' (click the card to retry)')
    }
  },
  series: [
    {
      data: [
        {
          name: "Catalogue",
          children: [
            {
              name: "Hardware",
              hasChildren: true
            },
            {
              name: "Software",
              hasChildren: true
            },
            {
              name: "Services",
              hasChildren: true
            }
          ]
        }
      ]
    }
  ],
  plotOptions: {
    tree: {
      orientation: "left-to-right",
      node: {
        template: "compact"
      },
      lazy: {
        load: (node) => new Promise((res, rej) => setTimeout(() => {
              if (node.name === 'Services' && fails-- > 0) return rej(new Error('timeout'))
              res([1, 2, 3, 4].map((i) => ({ name: node.name + ' ' + i, value: PG.int(10, 90), hasChildren: i === 1 })))
            }, PG.noAnim ? 0 : 600))
      }
    }
  },
  theme: {
    mode: "light",
    preset: "coastal"
  }
}

const chart = new WestCoastCharts(document.querySelector('#chart'), options)
await chart.render()

02 · Rendered state

Waiting for the chart.

Open Data & agent view to read this chart through chart.describe().

Read from the running library through its optional agent/describe module. Text, table and JSON share the same snapshot. Demo data only.

03 · CLIPublic tools

$ wcc chart export tree-lazy-children.json --out tree-lazy-children.svg --with-table

Public agent tools 0.2.3, tested with Library 1.1.5; available from the versioned GitHub release and npm. Save a JSON spec first and check the loaded runtime and supported modules before rendering. Command reference

04 · Markdown/gallery/tree/lazy-children/index.md

Loading /gallery/tree/lazy-children/index.md …

This example uses Premium modules. Compare licences · Embedding in a distributed product?