# Sankey

Represent quantities moving between nodes through link widths.

Canonical: https://chart.syidax.com/docs/components/sankey/

<a id="overview"></a>

## sy-sankey

Explain branching and merging flows of energy, users, or funds.

Keep link units consistent. Explain cases where inflow and outflow do not balance.

Base chart tier: Pro. Features such as additional renderers and custom branding have separate entitlement requirements.

| Input | Data description |
| --- | --- |
| `data` | { nodes?, links: [{ source, target, value }] }. |
| `nodeAlign` | How nodes align within stages. |

- [Run in Components](https://chart.syidax.com/charts/sankey) — Change options and view framework-specific code
- [Shared installation and integration](https://chart.syidax.com/docs/getting-started.md)

<a id="example"></a>

## Complete implementation example

```html
<div id="chart-container" style="width: 100%; min-width: 0;"></div>

<script type="module">
  import { defineCustomElement as define0 } from '@syidax/advanced-pro/components/sy-sankey.js';
  define0();

  // Pro: complete registerLicense at app startup using your issued certificate.
  // The website preview certificate is not for use in customer apps.
  const specs = [
    {
      "id": "example-chart",
      "tag": "sy-sankey",
      "props": {
        "data": {
          "links": [
            {
              "source": "Inflow",
              "target": "Product A",
              "value": 42
            },
            {
              "source": "Inflow",
              "target": "Product B",
              "value": 28
            },
            {
              "source": "Product A",
              "target": "Purchase",
              "value": 30
            },
            {
              "source": "Product A",
              "target": "Outflow",
              "value": 12
            },
            {
              "source": "Product B",
              "target": "Purchase",
              "value": 18
            },
            {
              "source": "Product B",
              "target": "Outflow",
              "value": 10
            }
          ]
        },
        "nodeAlign": "justify",
        "width": 640,
        "height": 360,
        "brandPosition": "bottom-right",
        "brandLogo": ""
      }
    }
  ];
  const container = document.querySelector('#chart-container');
  const elements = specs.map(({ tag, id, props }) => {
    const element = document.createElement(tag);
    element.id = id;
    Object.assign(element, props);
    element.setAttribute('aria-label', 'sankey example chart');
    return element;
  });
  container.replaceChildren(...elements);
  const chart = elements.at(-1);
  const onEvent = event => {
    console.log('nodeClick', event.detail);
  };
  chart.addEventListener('nodeClick', onEvent);
  const observer = new ResizeObserver(([entry]) => {
    const width = Math.max(160, Math.floor(entry.contentRect.width));
    elements.forEach(element => { element.width = width; });
  });
  observer.observe(container);

  // In an SPA, call this function when the view is disposed.
  function disposeChart() {
    observer.disconnect();
    chart.removeEventListener('nodeClick', onEvent);
    container.replaceChildren();
  }
</script>
```

<a id="props"></a>

## Properties

<a id="property-data"></a>

### data

{ nodes?, links: [{ source, target, value }] }.

| Item | Value |
| --- | --- |
| JavaScript property | `data` |
| HTML attribute | Pass objects, arrays, and callbacks as JavaScript properties |
| Type | `SankeyData` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

- [SankeyData](https://chart.syidax.com/docs/types/SankeyData.md) — Type definition

<a id="property-width"></a>

### width

Chart width in pixels. If the container width changes, update width from a ResizeObserver.

| Item | Value |
| --- | --- |
| JavaScript property | `width` |
| HTML attribute | `width` |
| Type | `number` |
| Default | `900` |

<a id="property-height"></a>

### height

Chart height in pixels. Allow space for axes, titles, and the legend.

| Item | Value |
| --- | --- |
| JavaScript property | `height` |
| HTML attribute | `height` |
| Type | `number` |
| Default | `400` |

<a id="property-brandLogo"></a>

### brandLogo

The default is the Syidax symbol and wordmark. With the Pro chart.branding entitlement, set none to remove it or provide a PNG, JPEG, or WebP data URL to replace it.

| Item | Value |
| --- | --- |
| JavaScript property | `brandLogo` |
| HTML attribute | `brand-logo` |
| Type | `string` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

<a id="property-brandPosition"></a>

### brandPosition

The corner where the logo is anchored. Community and Pro both support all four corners, using the same position on screen and in image exports.

| Item | Value |
| --- | --- |
| JavaScript property | `brandPosition` |
| HTML attribute | `brand-position` |
| Type | `'top-left' \| 'top-right' \| 'bottom-left' \| 'bottom-right'` |
| Default | `'bottom-right'` |
| Allowed values | `top-left`, `top-right`, `bottom-left`, `bottom-right` |

<a id="property-nodeWidth"></a>

### nodeWidth

The nodes' width and the gap between stacked nodes (CSS px).

| Item | Value |
| --- | --- |
| JavaScript property | `nodeWidth` |
| HTML attribute | `node-width` |
| Type | `number` |
| Default | `SANKEY_DEFAULT_NODE_WIDTH` |

<a id="property-nodePadding"></a>

### nodePadding

Set as an HTML attribute or JavaScript property. type: number.

| Item | Value |
| --- | --- |
| JavaScript property | `nodePadding` |
| HTML attribute | `node-padding` |
| Type | `number` |
| Default | `SANKEY_DEFAULT_NODE_PADDING` |

<a id="property-nodeAlign"></a>

### nodeAlign

How nodes align within stages.

| Item | Value |
| --- | --- |
| JavaScript property | `nodeAlign` |
| HTML attribute | `node-align` |
| Type | `SankeyAlign` |
| Default | `'justify'` |
| Allowed values | `left`, `right`, `center`, `justify` |

- [SankeyAlign](https://chart.syidax.com/docs/types/SankeyAlign.md) — Type definition

<a id="property-layoutIterations"></a>

### layoutIterations

the relaxation passes that reorder the rows to reduce crossings (d3-sankey's barycentre schedule; 0 = the declared order).

| Item | Value |
| --- | --- |
| JavaScript property | `layoutIterations` |
| HTML attribute | `layout-iterations` |
| Type | `number` |
| Default | `SANKEY_DEFAULT_ITERATIONS` |

<a id="property-color"></a>

### color

The nodes' fill: `auto` (the palette by index) or a CSS colour; a node's own `color` wins.

| Item | Value |
| --- | --- |
| JavaScript property | `color` |
| HTML attribute | `color` |
| Type | `string` |
| Default | `AUTO_COLOR` |

<a id="property-linkColor"></a>

### linkColor

The links' colour: `source` / `target` (the node's colour at that end) or a CSS colour; a link's own `color` wins.

| Item | Value |
| --- | --- |
| JavaScript property | `linkColor` |
| HTML attribute | `link-color` |
| Type | `string` |
| Default | `'source'` |

<a id="property-linkOpacity"></a>

### linkOpacity

The ribbons' opacity (0 … 1).

| Item | Value |
| --- | --- |
| JavaScript property | `linkOpacity` |
| HTML attribute | `link-opacity` |
| Type | `number` |
| Default | `DEFAULT_LINK_OPACITY` |

<a id="property-linkCurvature"></a>

### linkCurvature

the ribbons' centre line: 0 straight … 1 the full S-curve with horizontal tangents at both ends.

| Item | Value |
| --- | --- |
| JavaScript property | `linkCurvature` |
| HTML attribute | `link-curvature` |
| Type | `number` |
| Default | `SANKEY_DEFAULT_CURVATURE` |

<a id="property-nodeLabels"></a>

### nodeLabels

the node labels beside the nodes: `auto` (hidden where they would overlap), `show`, `hide`; `node-label-value` appends the throughput.

| Item | Value |
| --- | --- |
| JavaScript property | `nodeLabels` |
| HTML attribute | `node-labels` |
| Type | `SankeyLabelMode` |
| Default | `'auto'` |
| Allowed values | `auto`, `show`, `hide` |

- [SankeyLabelMode](https://chart.syidax.com/docs/types/SankeyLabelMode.md) — Type definition

<a id="property-nodeLabelValue"></a>

### nodeLabelValue

Set as an HTML attribute or JavaScript property. type: boolean.

| Item | Value |
| --- | --- |
| JavaScript property | `nodeLabelValue` |
| HTML attribute | `node-label-value` |
| Type | `boolean` |
| Default | `false` |

<a id="property-neighbourDim"></a>

### neighbourDim

with a hovered / focused node, the ribbons touching neither of its ends fade to this alpha factor (0 … 1; 1 = no dim).

| Item | Value |
| --- | --- |
| JavaScript property | `neighbourDim` |
| HTML attribute | `neighbour-dim` |
| Type | `number` |
| Default | `DEFAULT_NEIGHBOUR_DIM` |

<a id="property-activeColor"></a>

### activeColor

The hovered / focused node or link.

| Item | Value |
| --- | --- |
| JavaScript property | `activeColor` |
| HTML attribute | `active-color` |
| Type | `string` |
| Default | `DEFAULT_ACTIVE_COLOR` |

<a id="property-chartTitle"></a>

### chartTitle

The title inside the chart. Explain the data's unit and meaning alongside it.

| Item | Value |
| --- | --- |
| JavaScript property | `chartTitle` |
| HTML attribute | `chart-title` |
| Type | `string` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

<a id="property-chartSubtitle"></a>

### chartSubtitle

The subtitle inside the chart.

| Item | Value |
| --- | --- |
| JavaScript property | `chartSubtitle` |
| HTML attribute | `chart-subtitle` |
| Type | `string` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

<a id="property-enableMouseTracking"></a>

### enableMouseTracking

Set as an HTML attribute or JavaScript property. type: boolean.

| Item | Value |
| --- | --- |
| JavaScript property | `enableMouseTracking` |
| HTML attribute | `enable-mouse-tracking` |
| Type | `boolean` |
| Default | `true` |

<a id="property-tooltip"></a>

### tooltip

The tooltip (the shared cartesian tooltip input: trigger, format, html, connector …), its switch, a formatter of the default text.

| Item | Value |
| --- | --- |
| JavaScript property | `tooltip` |
| HTML attribute | Pass objects, arrays, and callbacks as JavaScript properties |
| Type | `CartesianTooltipInput` |
| Default | `undefined` |
| Literals in the type | `auto`, `off` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

- [CartesianTooltipInput](https://chart.syidax.com/docs/types/CartesianTooltipInput.md) — Type definition

<a id="property-tooltipEnabled"></a>

### tooltipEnabled

Set as an HTML attribute or JavaScript property. type: boolean.

| Item | Value |
| --- | --- |
| JavaScript property | `tooltipEnabled` |
| HTML attribute | `tooltip-show` |
| Type | `boolean` |
| Default | `true` |

<a id="property-tooltipFormat"></a>

### tooltipFormat

Pass as a JavaScript property. type: (detail: SankeyHitDetail) => string.

| Item | Value |
| --- | --- |
| JavaScript property | `tooltipFormat` |
| HTML attribute | Pass objects, arrays, and callbacks as JavaScript properties |
| Type | `(detail: SankeyHitDetail) => string` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

- [SankeyHitDetail](https://chart.syidax.com/docs/types/SankeyHitDetail.md) — Type definition

<a id="property-animated"></a>

### animated

Whether to animate initial display and data changes.

| Item | Value |
| --- | --- |
| JavaScript property | `animated` |
| HTML attribute | `animate` |
| Type | `boolean` |
| Default | `false` |

<a id="property-animationDuration"></a>

### animationDuration

Animation duration in milliseconds.

| Item | Value |
| --- | --- |
| JavaScript property | `animationDuration` |
| HTML attribute | `animation-duration` |
| Type | `number` |
| Default | `600` |

<a id="property-animationEasing"></a>

### animationEasing

Allowed values: linear, ease-out, ease-in, ease-in-out. Default: 'ease-out'.

| Item | Value |
| --- | --- |
| JavaScript property | `animationEasing` |
| HTML attribute | `animation-easing` |
| Type | `SankeyEasing` |
| Default | `'ease-out'` |
| Allowed values | `linear`, `ease-out`, `ease-in`, `ease-in-out` |

- [SankeyEasing](https://chart.syidax.com/docs/types/SankeyEasing.md) — Type definition

<a id="property-animationType"></a>

### animationType

Allowed values: initial, update. Default: undefined.

| Item | Value |
| --- | --- |
| JavaScript property | `animationType` |
| HTML attribute | `animation-type` |
| Type | `SankeyAnimationType` |
| Default | `undefined` |
| Allowed values | `initial`, `update` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

- [SankeyAnimationType](https://chart.syidax.com/docs/types/SankeyAnimationType.md) — Type definition

<a id="property-streamSource"></a>

### streamSource

§3.6: an external stream source (link upserts); without one the chart keeps its own on the first push.

| Item | Value |
| --- | --- |
| JavaScript property | `streamSource` |
| HTML attribute | Pass objects, arrays, and callbacks as JavaScript properties |
| Type | `SankeyStreamSource` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

- [SankeyStreamSource](https://chart.syidax.com/docs/types/SankeyStreamSource.md) — Type definition

<a id="property-streamMax"></a>

### streamMax

Links tracked by the internal stream at most (the oldest leave as `windowSlid`).

| Item | Value |
| --- | --- |
| JavaScript property | `streamMax` |
| HTML attribute | `stream-max` |
| Type | `number` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

<a id="property-streamWindow"></a>

### streamWindow

The newest N streamed links the chart renders (the whole buffer when unset).

| Item | Value |
| --- | --- |
| JavaScript property | `streamWindow` |
| HTML attribute | `stream-window` |
| Type | `number` |
| Default | `undefined` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

<a id="property-zoom"></a>

### zoom

Zoom: `'x'` | `'y'` | `'xy'` | `true` (x) enable the drag rectangle, the pan, the wheel, the pinch and the keyboard over the diagram's unit extents (x 0 → 1 left → right, y 0 → 1 bottom → top — the hidden frame's extents); an object refines `mode` / `drag` / `keyboard` / `minRangePx` / `resetButton` / `pan` / `wheel` / `pinch` / `inside`. Off by default. `zoomTo` / `zoomBy` / `panBy` / `resetZoom` work regardless of the gesture switches.

| Item | Value |
| --- | --- |
| JavaScript property | `zoom` |
| HTML attribute | Pass objects, arrays, and callbacks as JavaScript properties |
| Type | `CartesianZoomInput` |
| Default | `undefined` |
| Literals in the type | `auto`, `off`, `true`, `false`, `x`, `y`, `xy`, `inside` |

undefined means this property was not explicitly set. The effective value may depend on the chart type and other settings.

- [CartesianZoomInput](https://chart.syidax.com/docs/types/CartesianZoomInput.md) — Type definition

<a id="property-engine"></a>

### engine

Renderer selection: auto, standard, or pro. Engine selection is separate from permission to use a Pro chart type.

| Item | Value |
| --- | --- |
| JavaScript property | `engine` |
| HTML attribute | `engine` |
| Type | `SankeyEngineMode` |
| Default | `'auto'` |
| Allowed values | `auto`, `standard`, `pro` |

- [SankeyEngineMode](https://chart.syidax.com/docs/types/SankeyEngineMode.md) — Type definition

<a id="property-unavailable"></a>

### unavailable

Allowed values: fallback, error. Default: 'fallback'.

| Item | Value |
| --- | --- |
| JavaScript property | `unavailable` |
| HTML attribute | `unavailable` |
| Type | `SankeyUnavailableBehaviour` |
| Default | `'fallback'` |
| Allowed values | `fallback`, `error` |

- [SankeyUnavailableBehaviour](https://chart.syidax.com/docs/types/SankeyUnavailableBehaviour.md) — Type definition

<a id="events"></a>

## Events

<a id="event-rendered"></a>

### rendered

Emits rendering results in detail when chart drawing completes.

Event name: `rendered`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<SankeyRenderResult & { tier: SankeyEngineTier }>`.

```javascript
chart.addEventListener('rendered', event => {
  console.log(event.detail); // SankeyRenderResult & { tier: SankeyEngineTier }
});
```

- [SankeyRenderResult](https://chart.syidax.com/docs/types/SankeyRenderResult.md) — Type definition
- [SankeyEngineTier](https://chart.syidax.com/docs/types/SankeyEngineTier.md) — Type definition

<a id="event-nodeClick"></a>

### nodeClick

CustomEvent.detail type: SankeyNodeEventDetail. Event names are case-sensitive.

Event name: `nodeClick`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<SankeyNodeEventDetail>`.

```javascript
chart.addEventListener('nodeClick', event => {
  console.log(event.detail); // SankeyNodeEventDetail
});
```

- [SankeyNodeEventDetail](https://chart.syidax.com/docs/types/SankeyNodeEventDetail.md) — Type definition

<a id="event-nodeHover"></a>

### nodeHover

CustomEvent.detail type: SankeyNodeEventDetail | null. Event names are case-sensitive.

Event name: `nodeHover`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<SankeyNodeEventDetail | null>`.

```javascript
chart.addEventListener('nodeHover', event => {
  console.log(event.detail); // SankeyNodeEventDetail | null
});
```

- [SankeyNodeEventDetail](https://chart.syidax.com/docs/types/SankeyNodeEventDetail.md) — Type definition

<a id="event-linkClick"></a>

### linkClick

CustomEvent.detail type: SankeyLinkEventDetail. Event names are case-sensitive.

Event name: `linkClick`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<SankeyLinkEventDetail>`.

```javascript
chart.addEventListener('linkClick', event => {
  console.log(event.detail); // SankeyLinkEventDetail
});
```

- [SankeyLinkEventDetail](https://chart.syidax.com/docs/types/SankeyLinkEventDetail.md) — Type definition

<a id="event-linkHover"></a>

### linkHover

CustomEvent.detail type: SankeyLinkEventDetail | null. Event names are case-sensitive.

Event name: `linkHover`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<SankeyLinkEventDetail | null>`.

```javascript
chart.addEventListener('linkHover', event => {
  console.log(event.detail); // SankeyLinkEventDetail | null
});
```

- [SankeyLinkEventDetail](https://chart.syidax.com/docs/types/SankeyLinkEventDetail.md) — Type definition

<a id="event-selectionChanged"></a>

### selectionChanged

the selection (the pinned highlight) changed: a node or a link (never both) or nothing, and what changed it.

Event name: `selectionChanged`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<SankeySelectionChangeEventDetail>`.

```javascript
chart.addEventListener('selectionChanged', event => {
  console.log(event.detail); // SankeySelectionChangeEventDetail
});
```

- [SankeySelectionChangeEventDetail](https://chart.syidax.com/docs/types/SankeySelectionChangeEventDetail.md) — Type definition

<a id="event-pointContextMenu"></a>

### pointContextMenu

CustomEvent.detail type: ChartPointContextMenuEventDetail<SankeyHitDetail>. Event names are case-sensitive.

Event name: `pointContextMenu`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<ChartPointContextMenuEventDetail<SankeyHitDetail>>`.

```javascript
chart.addEventListener('pointContextMenu', event => {
  console.log(event.detail); // ChartPointContextMenuEventDetail<SankeyHitDetail>
});
```

- [ChartPointContextMenuEventDetail](https://chart.syidax.com/docs/types/ChartPointContextMenuEventDetail.md) — Type definition
- [SankeyHitDetail](https://chart.syidax.com/docs/types/SankeyHitDetail.md) — Type definition

<a id="event-appended"></a>

### appended

CustomEvent.detail type: { count: number; replaced: number }. Event names are case-sensitive.

Event name: `appended`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<{ count: number; replaced: number }>`.

```javascript
chart.addEventListener('appended', event => {
  console.log(event.detail); // { count: number; replaced: number }
});
```

<a id="event-windowSlid"></a>

### windowSlid

CustomEvent.detail type: { dropped: number }. Event names are case-sensitive.

Event name: `windowSlid`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<{ dropped: number }>`.

```javascript
chart.addEventListener('windowSlid', event => {
  console.log(event.detail); // { dropped: number }
});
```

<a id="event-tooltipShow"></a>

### tooltipShow

The shared tooltip events (the controller emits them).

Event name: `tooltipShow`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<CartesianTooltipEventDetail>`.

```javascript
chart.addEventListener('tooltipShow', event => {
  console.log(event.detail); // CartesianTooltipEventDetail
});
```

- [CartesianTooltipEventDetail](https://chart.syidax.com/docs/types/CartesianTooltipEventDetail.md) — Type definition

<a id="event-tooltipHide"></a>

### tooltipHide

CustomEvent.detail type: void. Event names are case-sensitive.

Event name: `tooltipHide`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<void>`.

```javascript
chart.addEventListener('tooltipHide', event => {
  console.log(event.detail); // void
});
```

<a id="event-tooltipAction"></a>

### tooltipAction

CustomEvent.detail type: CartesianTooltipActionEventDetail. Event names are case-sensitive.

Event name: `tooltipAction`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<CartesianTooltipActionEventDetail>`.

```javascript
chart.addEventListener('tooltipAction', event => {
  console.log(event.detail); // CartesianTooltipActionEventDetail
});
```

- [CartesianTooltipActionEventDetail](https://chart.syidax.com/docs/types/CartesianTooltipActionEventDetail.md) — Type definition

<a id="event-chartAnimationStart"></a>

### chartAnimationStart

CustomEvent.detail type: void. Event names are case-sensitive.

Event name: `chartAnimationStart`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<void>`.

```javascript
chart.addEventListener('chartAnimationStart', event => {
  console.log(event.detail); // void
});
```

<a id="event-chartAnimationEnd"></a>

### chartAnimationEnd

CustomEvent.detail type: void. Event names are case-sensitive.

Event name: `chartAnimationEnd`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<void>`.

```javascript
chart.addEventListener('chartAnimationEnd', event => {
  console.log(event.detail); // void
});
```

<a id="event-chartAnimationInterrupted"></a>

### chartAnimationInterrupted

CustomEvent.detail type: void. Event names are case-sensitive.

Event name: `chartAnimationInterrupted`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<void>`.

```javascript
chart.addEventListener('chartAnimationInterrupted', event => {
  console.log(event.detail); // void
});
```

<a id="event-zoomChange"></a>

### zoomChange

Fired after every zoom change (drag / pan / wheel / pinch / keyboard / api / reset) with the new state.

Event name: `zoomChange`. Names are case-sensitive. Read the payload from `detail` on `CustomEvent<CartesianZoomChangeEventDetail>`.

```javascript
chart.addEventListener('zoomChange', event => {
  console.log(event.detail); // CartesianZoomChangeEventDetail
});
```

- [CartesianZoomChangeEventDetail](https://chart.syidax.com/docs/types/CartesianZoomChangeEventDetail.md) — Type definition

<a id="methods"></a>

## Methods

<a id="method-redraw"></a>

### redraw

Redraw the chart using its current data and options. Inspect the rendered result after the returned Promise resolves.

```typescript
redraw(): Promise<SankeyRenderResult>
```

Return type: `Promise<SankeyRenderResult>`. Call the method after element registration and await its Promise result.

- [SankeyRenderResult](https://chart.syidax.com/docs/types/SankeyRenderResult.md) — Type definition

<a id="method-getActiveTier"></a>

### getActiveTier

An asynchronous method. Check the argument and return types below.

```typescript
getActiveTier(): Promise<SankeyEngineTier>
```

Return type: `Promise<SankeyEngineTier>`. Call the method after element registration and await its Promise result.

- [SankeyEngineTier](https://chart.syidax.com/docs/types/SankeyEngineTier.md) — Type definition

<a id="method-getUnavailableReason"></a>

### getUnavailableReason

Why the WebGPU renderer could not run (the fallback notice's reason); undefined when nothing fell back.

```typescript
getUnavailableReason(): Promise<string | undefined>
```

Return type: `Promise<string | undefined>`. Call the method after element registration and await its Promise result.

<a id="method-setData"></a>

### setData

Replace the bar set.

```typescript
setData(data: SankeyData): Promise<void>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `data` | `SankeyData` | Required |

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

- [SankeyData](https://chart.syidax.com/docs/types/SankeyData.md) — Type definition

<a id="method-appendPoint"></a>

### appendPoint

Append one value to the stream. Check the argument type and the licensing requirements for streaming.

```typescript
appendPoint(link: SankeyLinkInput): Promise<void>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `link` | `SankeyLinkInput` | Required |

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

- [SankeyLinkInput](https://chart.syidax.com/docs/types/SankeyLinkInput.md) — Type definition

<a id="method-appendBatch"></a>

### appendBatch

Append multiple values to the stream. Check the argument type and the licensing requirements for streaming.

```typescript
appendBatch(links: ReadonlyArray<SankeyLinkInput>): Promise<void>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `links` | `ReadonlyArray<SankeyLinkInput>` | Required |

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

- [SankeyLinkInput](https://chart.syidax.com/docs/types/SankeyLinkInput.md) — Type definition

<a id="method-shift"></a>

### shift

Drop the oldest streamed links (the `data` links are not the stream).

```typescript
shift(count: number): Promise<void>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `count` | `number` | Required |

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

<a id="method-replace"></a>

### replace

Swap the streamed set (`replace([])` clears it); the base `values` never leave. Without `chart.streaming` the dies upsert into the base like a batch (quietly: no `appended`, no `binChanged`, as a ring replace).

```typescript
replace(links: ReadonlyArray<SankeyLinkInput>): Promise<void>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `links` | `ReadonlyArray<SankeyLinkInput>` | Required |

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

- [SankeyLinkInput](https://chart.syidax.com/docs/types/SankeyLinkInput.md) — Type definition

<a id="method-getStreamSource"></a>

### getStreamSource

The stream session's source (Chart Pro): like the stream methods it waits for a license still being confirmed.

```typescript
getStreamSource(): Promise<SankeyStreamSource | undefined>
```

Return type: `Promise<SankeyStreamSource | undefined>`. Call the method after element registration and await its Promise result.

- [SankeyStreamSource](https://chart.syidax.com/docs/types/SankeyStreamSource.md) — Type definition

<a id="method-getEngineStatus"></a>

### getEngineStatus

Requested vs effective engine and why (CHART-ADD-08), with the chart.type.sankey license state.

```typescript
getEngineStatus(): Promise<ChartEngineStatus>
```

Return type: `Promise<ChartEngineStatus>`. Call the method after element registration and await its Promise result.

- [ChartEngineStatus](https://chart.syidax.com/docs/types/ChartEngineStatus.md) — Type definition

<a id="method-setAnimation"></a>

### setAnimation

An asynchronous method. Check the argument and return types below.

```typescript
setAnimation(options: { duration?: number; easing?: SankeyEasing; enabled?: boolean; type?: SankeyAnimationType }): Promise<void>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `options` | `{ duration?: number; easing?: SankeyEasing; enabled?: boolean; type?: SankeyAnimationType }` | Required |

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

- [SankeyEasing](https://chart.syidax.com/docs/types/SankeyEasing.md) — Type definition
- [SankeyAnimationType](https://chart.syidax.com/docs/types/SankeyAnimationType.md) — Type definition

<a id="method-pauseAnimation"></a>

### pauseAnimation

Pause the current animation.

```typescript
pauseAnimation(): Promise<void>
```

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

<a id="method-resumeAnimation"></a>

### resumeAnimation

Resume a paused animation.

```typescript
resumeAnimation(): Promise<void>
```

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

<a id="method-replayAnimation"></a>

### replayAnimation

Replay the initial sweep from min → value(s). No-op when animation is off / reduced.

```typescript
replayAnimation(): Promise<void>
```

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

<a id="method-hitTest"></a>

### hitTest

The node or link under a host-local CSS point (a node first, else the topmost ribbon), or null (always without a valid license).

```typescript
hitTest(cssX: number, cssY: number): Promise<SankeyHitDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `cssX` | `number` | Required |
| `cssY` | `number` | Required |

Return type: `Promise<SankeyHitDetail | null>`. Call the method after element registration and await its Promise result.

- [SankeyHitDetail](https://chart.syidax.com/docs/types/SankeyHitDetail.md) — Type definition

<a id="method-getNode"></a>

### getNode

An asynchronous method. Check the argument and return types below.

```typescript
getNode(index: number): Promise<SankeyNode | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `index` | `number` | Required |

Return type: `Promise<SankeyNode | null>`. Call the method after element registration and await its Promise result.

- [SankeyNode](https://chart.syidax.com/docs/types/SankeyNode.md) — Type definition

<a id="method-getNodeById"></a>

### getNodeById

An asynchronous method. Check the argument and return types below.

```typescript
getNodeById(id: string): Promise<SankeyNode | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `id` | `string` | Required |

Return type: `Promise<SankeyNode | null>`. Call the method after element registration and await its Promise result.

- [SankeyNode](https://chart.syidax.com/docs/types/SankeyNode.md) — Type definition

<a id="method-getNodes"></a>

### getNodes

An asynchronous method. Check the argument and return types below.

```typescript
getNodes(): Promise<SankeyNode[]>
```

Return type: `Promise<SankeyNode[]>`. Call the method after element registration and await its Promise result.

- [SankeyNode](https://chart.syidax.com/docs/types/SankeyNode.md) — Type definition

<a id="method-getLinks"></a>

### getLinks

An asynchronous method. Check the argument and return types below.

```typescript
getLinks(): Promise<SankeyLink[]>
```

Return type: `Promise<SankeyLink[]>`. Call the method after element registration and await its Promise result.

- [SankeyLink](https://chart.syidax.com/docs/types/SankeyLink.md) — Type definition

<a id="method-getNodeCount"></a>

### getNodeCount

An asynchronous method. Check the argument and return types below.

```typescript
getNodeCount(): Promise<number>
```

Return type: `Promise<number>`. Call the method after element registration and await its Promise result.

<a id="method-getLinkCount"></a>

### getLinkCount

An asynchronous method. Check the argument and return types below.

```typescript
getLinkCount(): Promise<number>
```

Return type: `Promise<number>`. Call the method after element registration and await its Promise result.

<a id="method-getExtent"></a>

### getExtent

An asynchronous method. Check the argument and return types below.

```typescript
getExtent(): Promise<SankeyExtent>
```

Return type: `Promise<SankeyExtent>`. Call the method after element registration and await its Promise result.

- [SankeyExtent](https://chart.syidax.com/docs/types/SankeyExtent.md) — Type definition

<a id="method-getLayoutStats"></a>

### getLayoutStats

the layout's statistics: the relaxation passes run, the proper crossings among the ribbons' centre lines (O(L²), on demand) and the energy Σ value × |y1 − y0| the relaxation minimises.

```typescript
getLayoutStats(): Promise<{ iterations: number; crossings: number; energy: number; curvature: number; crossingsComputed: boolean }>
```

Return type: `Promise<{ iterations: number; crossings: number; energy: number; curvature: number; crossingsComputed: boolean }>`. Call the method after element registration and await its Promise result.

<a id="method-getLabels"></a>

### getLabels

the placed node labels in HOST-local CSS px as shown (the plot offset added; under a zoom the labels of the nodes outside the window are left out), shown or hidden with the reason.

```typescript
getLabels(): Promise<SankeyNodeLabel[]>
```

Return type: `Promise<SankeyNodeLabel[]>`. Call the method after element registration and await its Promise result.

- [SankeyNodeLabel](https://chart.syidax.com/docs/types/SankeyNodeLabel.md) — Type definition

<a id="method-getLayout"></a>

### getLayout

The layout in HOST-local CSS px as shown (the plot offset added; under a zoom, the viewport transform applied; while an update morph runs, its current frame): the node rects, the ribbons, the scale.

```typescript
getLayout(): Promise<SankeyLayoutResult>
```

Return type: `Promise<SankeyLayoutResult>`. Call the method after element registration and await its Promise result.

- [SankeyLayoutResult](https://chart.syidax.com/docs/types/SankeyLayoutResult.md) — Type definition

<a id="method-showTooltipAtIndex"></a>

### showTooltipAtIndex

Open a tooltip by point index: nodes first, then directed links; null outside the graph or with the tooltip off.

```typescript
showTooltipAtIndex(index: number): Promise<CartesianTooltipEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `index` | `number` | Required |

Return type: `Promise<CartesianTooltipEventDetail | null>`. Call the method after element registration and await its Promise result.

- [CartesianTooltipEventDetail](https://chart.syidax.com/docs/types/CartesianTooltipEventDetail.md) — Type definition

<a id="method-hideTooltip"></a>

### hideTooltip

Close the currently visible tooltip.

```typescript
hideTooltip(): Promise<void>
```

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

<a id="method-focusNodeAt"></a>

### focusNodeAt

Move the keyboard focus ring to a node (null off the nodes); emits nodeHover like the walk.

```typescript
focusNodeAt(index: number): Promise<SankeyNodeEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `index` | `number` | Required |

Return type: `Promise<SankeyNodeEventDetail | null>`. Call the method after element registration and await its Promise result.

- [SankeyNodeEventDetail](https://chart.syidax.com/docs/types/SankeyNodeEventDetail.md) — Type definition

<a id="method-selectNodeAt"></a>

### selectNodeAt

Select (pin) a node: its neighbourhood stays highlighted after the pointer leaves; a negative or unknown index releases the selection. Emits selectionChanged when it changes.

```typescript
selectNodeAt(index: number): Promise<SankeyNodeEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `index` | `number` | Required |

Return type: `Promise<SankeyNodeEventDetail | null>`. Call the method after element registration and await its Promise result.

- [SankeyNodeEventDetail](https://chart.syidax.com/docs/types/SankeyNodeEventDetail.md) — Type definition

<a id="method-selectLinkAt"></a>

### selectLinkAt

Select (pin) a link: its ribbon keeps the accent after the pointer leaves; a negative or unknown index releases the selection.

```typescript
selectLinkAt(index: number): Promise<SankeyLinkEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `index` | `number` | Required |

Return type: `Promise<SankeyLinkEventDetail | null>`. Call the method after element registration and await its Promise result.

- [SankeyLinkEventDetail](https://chart.syidax.com/docs/types/SankeyLinkEventDetail.md) — Type definition

<a id="method-clearSelection"></a>

### clearSelection

Release the selection (emits selectionChanged when there was one).

```typescript
clearSelection(): Promise<void>
```

Return type: `Promise<void>`. Call the method after element registration and await its Promise result.

<a id="method-getSelection"></a>

### getSelection

The selection: the selected node's / link's detail (`null` = none); its anchors are Pro-derived, refused without a valid license.

```typescript
getSelection(): Promise<SankeySelection>
```

Return type: `Promise<SankeySelection>`. Call the method after element registration and await its Promise result.

- [SankeySelection](https://chart.syidax.com/docs/types/SankeySelection.md) — Type definition

<a id="method-zoomTo"></a>

### zoomTo

Zoom to explicit windows over the unit extents: `x` / `y` as `{ min, max }` or `[min, max]` (`null` clears that orientation).

```typescript
zoomTo(request: CartesianZoomRequest): Promise<CartesianZoomChangeEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `request` | `CartesianZoomRequest` | Required |

Return type: `Promise<CartesianZoomChangeEventDetail | null>`. Call the method after element registration and await its Promise result.

- [CartesianZoomChangeEventDetail](https://chart.syidax.com/docs/types/CartesianZoomChangeEventDetail.md) — Type definition
- [CartesianZoomRequest](https://chart.syidax.com/docs/types/CartesianZoomRequest.md) — Type definition

<a id="method-zoomBy"></a>

### zoomBy

Scale the current windows by `factor` (< 1 zooms in) around `anchorFraction` (0..1, default centre).

```typescript
zoomBy(factor: number, anchorFraction?: number): Promise<CartesianZoomChangeEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `factor` | `number` | Required |
| `anchorFraction` | `number` | Optional |

Return type: `Promise<CartesianZoomChangeEventDetail | null>`. Call the method after element registration and await its Promise result.

- [CartesianZoomChangeEventDetail](https://chart.syidax.com/docs/types/CartesianZoomChangeEventDetail.md) — Type definition

<a id="method-panBy"></a>

### panBy

Slide the zoomed windows by unit-extent units (`{ x?, y? }`); a no-op at the full extent.

```typescript
panBy(delta: { x?: number; y?: number }): Promise<CartesianZoomChangeEventDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `delta` | `{ x?: number; y?: number }` | Required |

Return type: `Promise<CartesianZoomChangeEventDetail | null>`. Call the method after element registration and await its Promise result.

- [CartesianZoomChangeEventDetail](https://chart.syidax.com/docs/types/CartesianZoomChangeEventDetail.md) — Type definition

<a id="method-resetZoom"></a>

### resetZoom

Reset the zoomed or panned range to the original data range.

```typescript
resetZoom(): Promise<CartesianZoomChangeEventDetail | null>
```

Return type: `Promise<CartesianZoomChangeEventDetail | null>`. Call the method after element registration and await its Promise result.

- [CartesianZoomChangeEventDetail](https://chart.syidax.com/docs/types/CartesianZoomChangeEventDetail.md) — Type definition

<a id="method-getZoom"></a>

### getZoom

Read the current zoom range. Check the return type's nullability and the range for each axis.

```typescript
getZoom(): Promise<CartesianZoomState | null>
```

Return type: `Promise<CartesianZoomState | null>`. Call the method after element registration and await its Promise result.

- [CartesianZoomState](https://chart.syidax.com/docs/types/CartesianZoomState.md) — Type definition

<a id="method-getZoomExtent"></a>

### getZoomExtent

The full extent (0 … 1) and key of the diagram's orientations (`null` before the first layout).

```typescript
getZoomExtent(request?: CartesianZoomExtentRequest): Promise<CartesianZoomExtentDetail | null>
```

| Arguments | Type | Required |
| --- | --- | --- |
| `request` | `CartesianZoomExtentRequest` | Optional |

Return type: `Promise<CartesianZoomExtentDetail | null>`. Call the method after element registration and await its Promise result.

- [CartesianZoomExtentDetail](https://chart.syidax.com/docs/types/CartesianZoomExtentDetail.md) — Type definition
- [CartesianZoomExtentRequest](https://chart.syidax.com/docs/types/CartesianZoomExtentRequest.md) — Type definition