index.html
<!DOCTYPE html>
<html>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>JSON Serialization - Copy layer by JSON</title>
<style type="text/css">
html,body{margin:0px;height:100%;width:100%}
.container{width:calc(50% - 2px);height:calc(100% - 2px);float:left;border:1px solid}
#map1{width:calc(50% - 2px);height:calc(100% - 2px);float:right;border:1px solid}
</style>
<link rel="stylesheet" href="https://unpkg.com/maptalks/dist/maptalks.css">
<script type="text/javascript" src="https://unpkg.com/maptalks/dist/maptalks.min.js"></script>
<body>
<div id="map" class="container"></div>
<div id="map1"></div>
<script>
var c = [-0.113049,51.498568];
var map = new maptalks.Map('map', {
center: c,
zoom: 13,
baseLayer: new maptalks.TileLayer('base', {
urlTemplate: 'https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png',
subdomains: ["a","b","c","d"],
attribution: '© <a href="http://osm.org">OpenStreetMap</a> contributors, © <a href="https://carto.com/">CARTO</a>'
}),
layers : [
new maptalks.VectorLayer('v0', [
new maptalks.Marker(c)
]),
new maptalks.VectorLayer('v1', [
new maptalks.Rectangle(c, 1000, 800)
])
]
});
var map1 = new maptalks.Map('map1', {
center: c,
zoom: 13,
baseLayer: new maptalks.TileLayer('base1', {
urlTemplate: 'https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png',
subdomains: ["a","b","c","d"],
attribution: '© <a href="http://osm.org">OpenStreetMap</a> contributors, © <a href="https://carto.com/">CARTO</a>'
})
});
// copy layer by JSON
maptalks.Layer.fromJSON(map.getLayer('v0').toJSON()).addTo(map1);
</script>
</body>
</html>