sandbox-react/leaflet-js-intg/app/components/map-array.jsx

81 lines
1.9 KiB
JavaScript

import React, { useEffect, useRef, useState } from 'react'
import L from 'leaflet'
import "leaflet/dist/leaflet.css";
import icon from "leaflet/dist/images/marker-icon.png";
import iconShadow from "leaflet/dist/images/marker-shadow.png";
let DefaultIcon = L.icon({
iconUrl: icon,
shadowUrl: iconShadow,
});
export default function MapArray( { array } ) {
console.log('map-array:MapArray: array.lngth: ' + array.length);
/*center map in the middle of RVB*/
const mapCenter = [52.16594, 10.52673];
const mapRef = useRef();
useEffect(() => {
const map = L.map(
mapRef.current,
{attributionControl: true}
).setView(
mapCenter,
6
);
L.tileLayer(
"http://{s}.tile.osm.org/{z}/{x}/{y}.png",
{
attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors',
maxZoom: 18,
scrollWheelZoom: false,
}).addTo(map);
array.map( function( value, key ) {
console.log('map-array:MapArray:map() value: ' +JSON.stringify(value));
L.Marker.prototype.options.icon = DefaultIcon;
var marker = L.marker(
[value.lat, value.lon],
{alt: 'popup marker name: ' + value.name}
).addTo(map);
const popupText ='name: <b>' + value.name + '</b><br />lat: ' + value.lat + '<br />lon: ' + value.lon;
marker.bindPopup(popupText);
});
// unmount map function
//You should unmount the function in react.js to remove the existing map.
return () => map.remove();
}, []);
if ( array !== undefined && array !== null && array.length > 0 ) {
return (
<>
<p>MapArray</p>
<div
style={{padding: 0, margin: 0, width: "75%", height: "23vh",}}
ref={el => mapRef.current = el}>
</div>
</>
);
}else{
//TODO Why does mapRef have to be present?
return (
<>
<p>MapArray loading...</p>
<div
ref={el => mapRef.current = el}>
</div>
</>
);
}
};
//https://github.com/azaharyan/react-leaflet-example