react-vega

react-vega

A lightweight React wrapper around vega-embed

Installation

npm i react-vega vega-embed vega-lite

If you need to use Vega (not Vega-Lite), you will also need to install vega.

npm i vega

Migrating to v8

In v8, the data prop was removed. Additionally, you can no longer update data by changing spec.data without the view being re-embedded. Instead use the View API to update data. See the Dynamic data recipe for an example.

The height and width props were removed. Additionally, you can no longer resize the view by changing spec.width or spec.height without the view being re-embedded. Instead use the View API to resize the view. See the Programmatically changing width & height recipe for an example.

The signalListeners prop was removed. Instead use the View API to subscribe to signal events. See the Subscribe to signal events recipe for an example.

Vega embed options are passed directly via the options prop, they are no longer flattened props on the VegaEmbed component.

Quick start

import { VegaEmbed } from "react-vega";

function Component() {
  return <VegaEmbed spec={spec} options={options} />;
}

or

import { useVegaEmbed } from "react-vega";

function Component() {
  const ref = React.useRef<HTMLDivElement>(null);
  const result = useVegaEmbed({ ref, spec, options });
  return <div ref={ref} />;
}

API

<VegaEmbed />

Prop	Type	Default	Notes
spec (required)	VisualizationSpec | string	—	Inline spec or URL. Accepts both Vega & Vega-Lite.
options	EmbedOptions	{}	Passed directly to embed().
onEmbed	(result: Result) => void	—	Called once embed() resolves. See Result for details.
onError	(err: unknown) => void	—	Called if embed() rejects.
...divProps	React.HTMLAttributes<HTMLDivElement>	—	Forwarded to the <div> element used for embedding.
ref	React.Ref<HTMLDivElement>	—	Forwarded to the <div> element used for embedding.

useVegaEmbed(params)

type UseVegaEmbedParams = {
  ref: React.RefObject<HTMLDivElement>;
  spec: VisualizationSpec | string;
  options?: EmbedOptions;
  onEmbed?: (r: Result) => void;
  onError?: (e: unknown) => void;
};

const result: Result | null = useVegaEmbed(params);

Returns the current Result (or null while loading).

Important

Any changes to spec or options will cause the view to be torn down and re-embedded. If you need to update the view without re-embedding, use the View API. Refer to the Recipes section for common use cases.

Recipes

See storybook for live examples.

1. Dynamic data

const ref = React.useRef<HTMLDivElement>(null);
const embed = useVegaEmbed({ ref, spec, options: { mode: "vega-lite" } });

useEffect(() => {
  embed?.view.data("values", data).runAsync();
}, [embed, data]);

2. Programmatically changing width & height

const embed = useVegaEmbed({
  ref,
  spec,
});

const changeDimensions = (width: number, height: number) => {
  embed?.view.width(width).height(height).runAsync();
};

3. Subscribe to signal events

const embed = useVegaEmbed({
  ref,
  spec,
});

useEffect(() => {
  const listener = (signal, data) => console.log(signal, data);

  embed?.view.addSignalListener("signal", listener);

  return () => {
    embed?.view.removeSignalListener("signal", listener);
  };
}, [embed]);

For more information see the documentation for vega-embed and the vega View API.

Contributing

• npm i
• npm run dev – run the storybook
• npm run test – run the test suite.