TrackAsia GL JS Docs
TrackAsiaTrackAsia GL JS DocsExamplesCreate a time slider

Create a time slider

Using Map#setFilter and D3.js, create a range slider to visualize earthquakes in 2015 that were greater than 5.9 magnitude.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Create a time slider</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://unpkg.com/trackasia-gl@1.0.5/dist/trackasia-gl.js"></script>
<link href="https://unpkg.com/trackasia-gl@1.0.5/dist/trackasia-gl.css" rel="stylesheet" />
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<style>
.map-overlay {
font: 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;
position: absolute;
width: 25%;
top: 0;
left: 0;
padding: 10px;
}
 
.map-overlay .map-overlay-inner {
background-color: #fff;
box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
border-radius: 3px;
padding: 10px;
margin-bottom: 10px;
}
 
.map-overlay h2 {
line-height: 24px;
display: block;
margin: 0 0 10px;
}
 
.map-overlay .legend .bar {
height: 10px;
width: 100%;
background: linear-gradient(to right, #fca107, #7f3121);
}
 
.map-overlay input {
background-color: transparent;
display: inline-block;
width: 100%;
position: relative;
margin: 0;
cursor: ew-resize;
}
</style>
 
<div id="map"></div>
 
<div class="map-overlay top">
<div class="map-overlay-inner">
<h2>Significant earthquakes in 2015</h2>
<label id="month"></label>
<input id="slider" type="range" min="0" max="11" step="1" value="0" />
</div>
<div class="map-overlay-inner">
<div id="legend" class="legend">
<div class="bar"></div>
<div>Magnitude (m)</div>
</div>
</div>
</div>
 
<script src="https://d3js.org/d3.v3.min.js" charset="utf-8"></script>
<script>
var map = new trackasiagl.Map({
container: 'map',
style: 'https://maps.track-asia.com/styles/v1/streets.json?key=public_key',
center: {"lat":10.762622,"lng":106.660172},
zoom: 0.5
});
 
var months = [
'January',
'February',
'March',
'April',
'May',
'June',
'July',
'August',
'September',
'October',
'November',
'December'
];
 
function filterBy(month) {
var filters = ['==', 'month', month];
map.setFilter('earthquake-circles', filters);
map.setFilter('earthquake-labels', filters);
 
// Set the label to the month
document.getElementById('month').textContent = months[month];
}
 
map.on('load', function () {
// Data courtesy of http://earthquake.usgs.gov/
// Query for significant earthquakes in 2015 URL request looked like this:
// http://earthquake.usgs.gov/fdsnws/event/1/query
//    ?format=geojson
//    &starttime=2015-01-01
//    &endtime=2015-12-31
//    &minmagnitude=6'
//
// Here we're using d3 to help us make the ajax request but you can use
// Any request method (library or otherwise) you wish.
d3.json(
'https://docs.track-asia.com/assets/significant-earthquakes-2015.geojson',
function (err, data) {
if (err) throw err;
 
// Create a month property value based on time
// used to filter against.
data.features = data.features.map(function (d) {
d.properties.month = new Date(d.properties.time).getMonth();
return d;
});
 
map.addSource('earthquakes', {
'type': 'geojson',
data: data
});
 
map.addLayer({
'id': 'earthquake-circles',
'type': 'circle',
'source': 'earthquakes',
'paint': {
'circle-color': [
'interpolate',
['linear'],
['get', 'mag'],
6,
'#FCA107',
8,
'#7F3121'
],
'circle-opacity': 0.75,
'circle-radius': [
'interpolate',
['linear'],
['get', 'mag'],
6,
20,
8,
40
]
}
});
 
map.addLayer({
'id': 'earthquake-labels',
'type': 'symbol',
'source': 'earthquakes',
'layout': {
'text-field': [
'concat',
['to-string', ['get', 'mag']],
'm'
],
'text-font': [
'DIN Pro Regular',
'Arial Unicode MS Regular'
],
'text-size': 12
},
'paint': {
'text-color': 'rgba(0,0,0,0.5)'
}
});
 
// Set filter to first month of the year
// 0 = January
filterBy(0);
 
document
.getElementById('slider')
.addEventListener('input', function (e) {
var month = parseInt(e.target.value, 10);
filterBy(month);
});
}
);
});
</script>
 
</body>
</html>