index.html
<!DOCTYPE html>
<html>
<head>
<title>Leaflet TopoJSON Example</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
<link rel="stylesheet" href="//cdn.leafletjs.com/leaflet-0.6.4/leaflet.css" />
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="//cdn.leafletjs.com/leaflet-0.6.4/leaflet.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<style>
body {
padding: 0;
margin: 0;
}
html, body, #map {
height: 100%;
}
</style>
</head>
<body>
<div id="map"></div>
<script src="some-javascripts.js"></script>
</body>
</html>
some-javascripts.js
var county_layer = L.geoJson(null, {
style: {
color: '#e2e3e3',
weight: 1,
opacity: 1,
fillOpacity: 0.3
}
}),
state_layer = L.geoJson(null, {
style: {
color: '#fff',
weight: 3,
opacity: 1,
fillOpacity: 0
}
}),
map = L.map('map');
L.tileLayer('http://{s}.tiles.mapbox.com/v3/landplanner.map-oxe99jxb/{z}/{x}/{y}.png', {
maxZoom: 17,
attribution: 'Map data © Someone, Somewhere.',
}).addTo(map);
map
.addLayer(county_layer)
.addLayer(state_layer)
.setView([40, -100], 5);
$.getJSON('us_counties.json', function (data) {
var county_geojson = topojson.feature(data, data.objects.counties),
state_geojson = topojson.feature(data, data.objects.states);
county_layer.addData(county_geojson);
state_layer.addData(state_geojson);
});