react-esri-leaflet v2.0.1

Requirements

Requires react^18, react-leaflet^4, and esri-leaflet^3.

Installation

To use these components you must install certain dependencies yourself:

npm i react react-dom leaflet react-leaflet esri-leaflet

with all of your underlying packages installed,

npm i react-esri-leaflet

Components

react-esri-leaflet offers the following components:

Native Components:

• <BasemapLayer />
• <FeatureLayer />
• <TiledMapLayer />
• <ImageMapLayer />
• <DynamicMapLayer />

Plugins:

• <EsriLeafletGeoSearch />
• <HeatmapLayer />
• <ClusterLayer />
• <VectorBasemapLayer />
• <VectorTileLayer />

Use

Import any of the components and use them in a <MapContainer />:

import React from "react";
import { MapContainer } from "react-leaflet";
import { BasemapLayer, FeatureLayer } from "react-esri-leaflet";
import EsriLeafletGeoSearch from "react-esri-leaflet/plugins/GeoSearch";

const Map = () => {
  return (
    <MapContainer zoom={zoom} center={center}>
      <BasemapLayer name="DarkGray" />
      <FeatureLayer url={featureLayerURL} />
      <EsriLeafletGeoSearch useMapBounds={false} position="topright" />
    </MapContainer>
  );
};

Using esri-leaflet Plugins

If you want to use any of the esri-leaflet plugins, you must first install their underlying packages and any associated css. Each plugin has its own requirements, which you can find in the esri-leaflet docs. Plugins are imported not from the main package, but from the /plugins/<PluginName> subfolder, like this:

import EsriLeafletGeoSearch from "react-esri-leaflet/plugins/EsriLeafletGeoSearch";

EsriLeafletGeoSearch

You must first install the underlying esri-leaflet-geocoder:

npm i esri-leaflet-geocoder

You will also need to include the css in your html header, as explained in the esri-leaflet-geocoder documentation. You can then use the <EsriLeafletGeoSearch /> component. See the Use section for examples.

HeatmapLayer

First install the underlying dependencies:

npm i leaflet.heat esri-leaflet-heatmap

You can then use the <HeatmapLayer /> component.

ClusterLayer

First install the underlying dependencies:

npm i leaflet.markercluster esri-leaflet-cluster

You can then use the <ClusterLayer /> component.

VectorBasemapLayer and VectorTileLayer

First install the underlying dependencies:

npm i esri-leaflet-vector

You can then use the <VectorBasemapLayer /> and <VectorTileLater /> components.

Props

All react-esri-leaflet components inherit their props from the underlying esri-leaflet component options. You can find the options for each esri-leaflet layer in their documentation. However, certain options are available or necessary for react-esri-leaflet components:

<EsriLeafletGeoSearch 
  providers={{
    arcgisOnlineProvider: {
      token: your_token,
      label: "ArcGIS Online Results",
      maxResults: 10
    },
    featureLayerProvider: {
      url: feature_layer_url,
      label: 'Featurelayer Provider Results'
      bufferRadius: 5000
    }
  }}
/>;

Events

Events can be accessed in the same way as described in the react-leaflet documentation, using the eventHandlers prop. All events are inherited from their underlying esri-leaflet component. For example:

<FeatureLayer
  url={'featureLayerURL'}
  eventHandlers={{
    loading: () => console.log('featurelayer loading'),
    load: () => console.log('featurelayer loaded')
  }} />

<EsriLeafletGeoSearch
  position="topright"
  eventHandlers={{
    requeststart: () => console.log('Started request...'),
    requestend: () => console.log('Ended request...'),
    results: (r) => console.log(r)
  }} />

Methods

Many of the methods on esri-leaflet layers can be handled through react props. For example, a <FeatureLayer /> accepts the where prop, which applies a server side filter on the features in the layer. Using vanilla esri-leaflet, the getWhere and setWhere methods are available on the layer. With react-esri-leaflet, you can manage the setting and getting of many layer properties with react:

const Map = () => {

  const [minPopulation, setMinpopulation] = useState(1000);

  return (
    <MapContainer zoom={zoom} center={center}>

      <FeatureLayer
        where={`Population > '${minPopulation}'`}
        url={featureLayerURL}
      />

      <button onClick={() => setMinpopulation(5000)}>
        Set min population to 5000
      </button>

    </MapContainer>
  );

};

In this way, you can 'get' or 'set' your prop by accessing the state variable used to control it, or setting that state variable.

Other methods on esri-leaflet components are less related to presentational logic, and more related to analysis or interacting with the root dataset. For example, calling query or eachFeature on a featureLayer will not affect the presentation logic. In this sense, all methods not directly affecting the presentational logic of your layers (read: everything but the setters and getters) should be accessed by getting a ref to the underlying esri-leaflet layer. For example:

const Map = () => {

  const featureLayerRef = useRef();

  const queryFeature = () => {
    featureLayerRef.current
      .query()
      .within(latlngbounds)
      .where("Direction = 'WEST'")
      .run(function (error, featureCollection) {
        console.log(featureCollection);
      });
  };

  return (
    <MapContainer zoom={zoom} center={center}>
      <FeatureLayer ref={featureLayerRef} url={featureLayerURL} />
      <button onClick={queryFeature}>Run a Query</button>
    </MapContainer>
  );

};

Using Authenticated Layers

Any esri layers that require authentication accept a token prop. A react-esri-leaflet layer that requires a token should be conditionally rendered based on the availability of the token. For example, a typical token getting function is as follows:

async function authenticateEsri(client_id, client_secret, expiration) {

  const authservice = "https://www.arcgis.com/sharing/rest/oauth2/token";
  const url = `${authservice}?client_id=${client_id}&client_secret=${client_secret}&grant_type=client_credentials&expiration=${expiration}`;

  let token;

  await fetch(url, {
    method: "POST"
  })
    .then((res) => res.json())
    .then((res) => {
      token = res.access_token;
    })
    .catch((error) => {
      console.error(error);
    });

  return token;

}

On component mount, you can call this function, save the token to state, and conditionally render the layer based on the state variable:

const Map = (props) => {

  const [token, setToken] = useState(null);

  useEffect(() => {
    async function getToken() {
      const token = await authenticateEsri();
      setToken(token);
    }
    getToken();
  }, []);

  return (
    <MapContainer zoom center>
      {token && (
        <>
          <ImageMapLayer
            token={token}
            url="https://landscape6.arcgis.com/arcgis/rest/services/World_Land_Cover_30m_BaseVue_2013/ImageServer"
          />
          <VectorBasemapLayer name="ArcGIS:Streets" token={token} />
        </>
      )}
    </MapContainer>
  );
  
};

Alternatives

You don't necesarily need an esri-leaflet component to bring esri layers into leaflet. You can use an esri service url with a react-leaflet TileLayer. For example:

<TileLayer url="https://server.arcgisonline.com/ArcGIS/rest/services/Ocean_Basemap/MapServer/tile/{z}/{y}/{x}">

is equivalent to

<Basemap name="Oceans">

Esri also offers react-arcgis, which is a react wrapper for the ArcGIS Javascript API, but that takes you outside the realm of leaflet.

License

MIT License