The symbols and renderer for a feature layer can be stored in the feature service. This sample demonstrates how to recreate the symbology on the client using the Esri Leaflet Renderers plugin.
<html>
<head>
<meta charset="utf-8" />
<title>Display feature layer symbols</title>
<meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no" />
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" crossorigin="" />
<script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js" crossorigin=""></script>
<!-- Load Esri Leaflet from CDN -->
<script src="https://unpkg.com/esri-leaflet@3.0.12/dist/esri-leaflet.js"></script>
<!-- Load Esri Leaflet Renderers from CDN -->
<script src="https://unpkg.com/esri-leaflet-renderers@3.0.1" crossorigin=""></script>
<!-- Load Esri Leaflet Vector from CDN -->
<script src="https://unpkg.com/esri-leaflet-vector@4.2.5/dist/esri-leaflet-vector.js" crossorigin=""></script>
<style>
html,
body,
#map {
padding: 0;
margin: 0;
height: 100%;
width: 100%;
font-family: Arial, Helvetica, sans-serif;
font-size: 14px;
color: #323232;
}
</style>
</head>
<body>
<div id="map"></div>
<script>
const accessToken = "YOUR_ACCESS_TOKEN";
const map = L.map("map").setView([37.837, -122.479], 6);
L.esri.Vector.vectorBasemapLayer("arcgis/light-gray/base", {
token: accessToken
}).addTo(map);
// renderer type: unique value
L.esri
.featureLayer({
url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Earthquakes_Since1970/MapServer/0"
})
.addTo(map);
</script>
</body>
</html>