How to pass state down to child component's handler?

Question

The GeoJson component has a function onEachFeature that calls a handler, in this case it is createPopup.

<GeoJSON data={covidGeoJSON} onEachFeature={createPopup}></GeoJSON>

Within the handler createPopup how can I access states defined inside the CovidMap component?

import React, { useState } from 'react'
import { MapContainer, GeoJSON } from 'react-leaflet'
import 'leaflet/dist/leaflet.css'



CovidMap = ({ covidGeoJSON, styles }) => {

    const showCords = (e) => {
        console.log(e.latlng);
    }

    const createPopup = (state, layer) => {
        layer.on({
            mouseover: showCords,
        });
        layer.bindPopup(state.properties.NAME);
    }

    const [range, setRange] = useState([]);

    return (
        <div>
            <MapContainer style={{ height: '90vh', width: '100vw' }} center={[39.162497380360634, -94.83672007881789]} zoom={5}>
                <GeoJSON data={covidGeoJSON} onEachFeature={createPopup}></GeoJSON>
            </MapContainer>
        </div>
    )
}

export default CovidMap

Answer 1

You should be able to reference the state from createPopup. Create & use state variables within CovidMap using the useState hook:

const CovidMap = () => {

    ...
    const [properties, setProperties] = useState({});
    const [layer, setLayer] = useState({});

    const createPopup = () => {
        layer.on({
            mouseover: showCords,
        });
        layer.bindPopup(properties.NAME);
    }
    ...
}