# Draggable Nodes (Sankey example)

> WestCoast Charts 1.1.5, release, public Core release, on npm. HTML: https://westcoast-charts.com/gallery/sankey/draggable-nodes/ · Index for agents: https://westcoast-charts.com/llms.txt

Drag a node up or down; links follow and the position survives updates. nodeMove reports the offset.

- Chart type: `sankey` (Sankey)
- Collection: Sankey · Sankey
- Raw configuration: https://westcoast-charts.com/gallery-src/sankey/draggable-nodes.js
- Standalone example: https://westcoast-charts.com/embed/samples/wcc/gallery/premium/sankey/draggable-nodes.html

## Setup

```js
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
```

## Options

```js
const options = {
  chart: {
    height: 420,
    toolbar: {
      show: false
    },
    type: "sankey",
    events: {
      nodeMove: (e, ctx, o) => log(`nodeMove ${o.node.name}: ${Math.round(o.offset)} px`)
    }
  },
  series: [
    {
      data: [
        ["Coal", "Electricity", 22],
        ["Gas", "Electricity", 30],
        ["Gas", "Heat", 26],
        ["Wind", "Electricity", 28],
        ["Solar", "Electricity", 14],
        ["Electricity", "Industry", 40],
        ["Electricity", "Homes", 34],
        ["Electricity", "Losses", 20],
        ["Heat", "Homes", 18],
        ["Heat", "Industry", 8]
      ]
    }
  ],
  plotOptions: {
    sankey: {
      draggable: true
    }
  },
  theme: {
    mode: "light",
    preset: "coastal"
  }
}

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

## Verify

- Text check (Library 1.1.5): load `west-coast-charts/agent/describe` and call `chart.describe({ format: "json" })` for the actual drawn state. The live reader is on this example’s HTML page.
- Command line (Public agent tools 0.2.3, tested with Library 1.1.5; available from the versioned GitHub release and npm, https://westcoast-charts.com/docs/cli/index.md): `wcc chart export sankey-draggable-nodes.json --out sankey-draggable-nodes.svg --with-table` (save the options above as JSON first)