Maps - Kumo Svelte

Loading example...

const cloudflareLocations = [
  { city: "San Francisco", iata: "SFO", lat: 37.77, lon: -122.42 },
  { city: "London", iata: "LHR", lat: 51.51, lon: -0.13 },
  { city: "Singapore", iata: "SIN", lat: 1.35, lon: 103.82 },
  // ...more locations
];

<BubbleMap
  echarts={echarts}
  geoJson={geoJson}
  data={cloudflareLocations}
  lng="lon"
  lat="lat"
  name="city"
  value={() => 1}
  bubbleColor="#F6821F"
  minRadius={8}
  maxRadius={8}
  tooltipFormatter={(row) =>
    "<strong>" + row.city + "</strong> " + row.iata
  }
/>

Installation

BubbleMap and ChoroplethMap require echarts as a peer dependency. Consumers provide the GeoJSON feature collection; map components do not fetch map data or use map tiles.

npm install echarts

Barrel

import { BubbleMap, ChoroplethMap } from "kumo-svelte";

Granular

import { BubbleMap, ChoroplethMap } from "kumo-svelte/components/chart";

Usage

import { BubbleMap, ChoroplethMap, type MapGeoJson } from "kumo-svelte";
import * as echarts from "echarts/core";
import { MapChart, ScatterChart } from "echarts/charts";
import { TooltipComponent, VisualMapComponent } from "echarts/components";
import { CanvasRenderer } from "echarts/renderers";

echarts.use([
  MapChart,
  ScatterChart,
  TooltipComponent,
  VisualMapComponent,
  CanvasRenderer,
]);

// Load GeoJSON in your app and pass it to map components.
const geoJson = world as MapGeoJson;

const colos = [
  { iata: "SFO", city: "San Francisco", lat: 37.77, lon: -122.42, requests: 1200 },
  { iata: "LHR", city: "London", lat: 51.5, lon: -0.12, requests: 1500 },
];

const countries = [
  { country: "United States of America", requests: 4200 },
  { country: "Germany", requests: 3100 },
];

<BubbleMap
  echarts={echarts}
  geoJson={geoJson}
  data={colos}
  lng="lon"
  lat="lat"
  name="city"
  value="requests"
/>

<ChoroplethMap
  echarts={echarts}
  geoJson={geoJson}
  data={countries}
  name="country"
  value="requests"
/>

Examples

Bubble Map

Plot raw rows by longitude and latitude. The value accessor controls proportional bubble size.

Loading example...

<BubbleMap
  echarts={echarts}
  geoJson={geoJson}
  data={colos}
  lng="lon"
  lat="lat"
  name="city"
  value="requests"
  minRadius={8}
/>

Choropleth Map

Shade regions by value. Data rows are joined to GeoJSON features by name, matched against the feature's nameProperty, which defaults to "name".

Loading example...

<ChoroplethMap
  echarts={echarts}
  geoJson={geoJson}
  data={countries}
  name="country"
  value="requests"
/>

Custom Tooltips

Provide tooltipFormatter when the default name/value tooltip is not enough. The formatter returns HTML rendered by ECharts, so escape user-provided values.

<BubbleMap
  echarts={echarts}
  geoJson={geoJson}
  data={colos}
  lng="lon"
  lat="lat"
  name="city"
  value="requests"
  tooltipFormatter={(row) =>
    "<strong>" + row.city + "</strong><br />" + row.requests.toLocaleString()
  }
/>

API Reference

BubbleMap

Prop	Type	Default	Description
echarts *	`any`	-	The ECharts core instance imported by the consumer.
geoJson *	`MapGeoJson`	-	GeoJSON FeatureCollection for the map base.
mapName	`string`	-	Stable ECharts map registry name. Invalid characters are replaced with dashes.
data *	`T[]`	-	Rows to plot as bubbles.
lng *	`MapAccessor<T, number>`	-	Longitude accessor: a row key or function.
lat *	`MapAccessor<T, number>`	-	Latitude accessor: a row key or function.
value *	`MapAccessor<T, number>`	-	Numeric value accessor used to size bubbles.
name	`MapAccessor<T, string>`	-	Optional label accessor used by the default tooltip.
minRadius	`number`	`6`	Smallest bubble radius in pixels.
maxRadius	`number`	`26`	Largest bubble radius in pixels.
bubbleSize	`(value: number) => number`	-	Explicit bubble radius function. Overrides minRadius/maxRadius scaling.
bubbleColor	`MapStyle<T, string>`	-	Bubble fill color as a constant or row function.
bubbleBorderColor	`MapStyle<T, string>`	`"transparent"`	Bubble border color as a constant or row function.
bubbleBorderWidth	`MapStyle<T, number>`	`0`	Bubble border width as a constant or row function.
center	`[number, number]`	-	Map center as [longitude, latitude]. Defaults to auto-fit.
zoom	`number`	`1.25`	Zoom level as a multiple of the auto-fit scale.
roam	`boolean`	`false`	Enables drag-to-pan and scroll-to-zoom.
projection	`MapProjection \| null`	-	Geographic projection. Defaults to latitude-clamped Mercator; use null for raw coordinates.
aspectRatio	`number \| string`	-	Container aspect ratio. Defaults to the projected map window.
showTooltip	`boolean`	`true`	Whether to show the default map tooltip.
valueFormat	`(value: number) => string`	-	Formats values in the default tooltip.
tooltipFormatter	`(row: T) => string`	-	Custom HTML tooltip formatter. Escape user-provided strings before returning.
onBubbleHover	`(row: T \| undefined) => void`	-	Callback fired as the pointer enters or leaves a bubble.
onBubbleClick	`(row: T) => void`	-	Callback fired when a bubble is clicked.
height	`number`	-	Fixed chart height in pixels. Overrides aspectRatio.
isDarkMode	`boolean`	-	When true, switches map and bubble palette choices for dark mode.

ChoroplethMap

Prop	Type	Default	Description
echarts *	`any`	-	The ECharts core instance imported by the consumer.
geoJson *	`MapGeoJson`	-	GeoJSON FeatureCollection whose regions are shaded by value.
mapName	`string`	-	Stable ECharts map registry name. Invalid characters are replaced with dashes.
data *	`T[]`	-	Rows joined to GeoJSON features.
name *	`MapAccessor<T, string>`	-	Region key accessor used to join rows to GeoJSON features.
value *	`MapAccessor<T, number>`	-	Numeric value accessor used for the region fill scale.
nameProperty	`string`	`"name"`	GeoJSON feature property used for the data join.
colorRange	`string[]`	-	Sequential color ramp from low to high values.
min	`number`	-	Lower bound for the continuous scale.
max	`number`	-	Upper bound for the continuous scale.
noDataColor	`string`	-	Fill color for GeoJSON regions without a matching data row.
showLegend	`boolean`	`false`	Whether to show the ECharts visualMap legend.
showTooltip	`boolean`	`true`	Whether to show the default map tooltip.
valueFormat	`(value: number) => string`	-	Formats values in the default tooltip.
tooltipFormatter	`(row: T) => string`	-	Custom HTML tooltip formatter. Escape user-provided strings before returning.
center	`[number, number]`	-	Map center as [longitude, latitude]. Defaults to auto-fit.
zoom	`number`	`1.25`	Zoom level as a multiple of the auto-fit scale.
roam	`boolean`	`false`	Enables drag-to-pan and scroll-to-zoom.
projection	`MapProjection \| null`	-	Geographic projection. Defaults to latitude-clamped Mercator; use null for raw coordinates.
aspectRatio	`number \| string`	-	Container aspect ratio. Defaults to the projected map window.
height	`number`	-	Fixed chart height in pixels. Overrides aspectRatio.
isDarkMode	`boolean`	-	When true, switches map and region palette choices for dark mode.
chartRef	`EChartsType \| null`	-	Bindable chart instance reference.
onRegionHover	`(row: T \| undefined) => void`	-	Callback fired as the pointer enters or leaves a region with data.
onRegionClick	`(row: T) => void`	-	Callback fired when a region with data is clicked.