react-leaflet-choropleth

This component extends geoJson from react-leaflet and will use chroma to set the color, using a property or function value. This is highly based on leaflet-choropleth by timwis.

Installation

npm install react-leaflet-choropleth

Options

Required

data: geojson data as a FeatureCollection our as an array.

style: Styling to be applied to each geojson object. Can be a function or an object.

valueProperty: The way a value is obtained from each geojson object. Can be a function like function(feature){ return feature.properties.value } or it will use the propert to look up on the value in the properties object on the geojson shape.

scale: An array of the top and bottom colors to use.

steps: A number to determine how many different colors to pick from.

mode: The mode to use from chroma.js. This can be 'e' from equadistant, 'q' for quantile or 'k' for k-means.

Optional

visible:A way to determine whether to use the fillColor provided in styles, or to use the fillColor of the choropleth. Useful for overwriting the choropleth color.

ref: A way to get the leaflet geojson Object. <ref>.leafletElement will be a FeatureGroup containing the leaflet layers created.

identity: A function used to set the key prop for each geojson feature

All other props passed to Choropleth will also be passed to each geojson layer.

Example

import Choropleth from 'react-leaflet-choropleth'
import { Map } from 'react-leaflet'

const style = {
    fillColor: '#F28F3B',
    weight: 2,
    opacity: 1,
    color: 'white',
    dashArray: '3',
    fillOpacity: 0.5
}

const map = (geojson) => (
  <Map>
    <Choropleth
      data={{type: 'FeatureCollection', features: geojson}}
      valueProperty={(feature) => feature.properties.value}
      visible={(feature) => feature.id !== active.id}
      scale={['#b3cde0', '#011f4b']}
      steps={7}
      mode='e'
      style={style}
      onEachFeature={(feature, layer) => layer.bindPopup(feature.properties.label)}
      ref={(el) => this.choropleth = el.leafletElement}
    />
  </Map>
)