Skip to content

Instantly share code, notes, and snippets.

@chaseleinart
Created January 7, 2026 01:59
Show Gist options
  • Select an option

  • Save chaseleinart/c4c417c93ffa04bebc48bc2e0a3516c0 to your computer and use it in GitHub Desktop.

Select an option

Save chaseleinart/c4c417c93ffa04bebc48bc2e0a3516c0 to your computer and use it in GitHub Desktop.
<!DOCTYPE html>
<html>
<head>
<title>leaflet-map-csv</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta charset="utf-8">
<!-- Load Leaflet code library - see updates at http://leafletjs.com/download.html -->
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.7.1/dist/leaflet.css"/>
<script src="https://unpkg.com/leaflet@1.7.1/dist/leaflet.js"></script>
<!-- Load jQuery and PapaParse to read data from a CSV file -->
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/papaparse@5.3.0/papaparse.min.js"></script>
<!-- Position the map with Cascading Style Sheet (CSS) -->
<style>
body { margin:0; padding:0; font-family: Arial, sans-serif; }
#map { position: absolute; top:0; bottom:0; right:0; left:0; display: none; }
#upload-container {
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
background: #f5f5f5;
}
#upload-box {
background: white;
padding: 40px;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
text-align: center;
}
#file-input {
margin: 20px 0;
padding: 10px;
}
</style>
</head>
<body>
<!-- File upload interface -->
<div id="upload-container">
<div id="upload-box">
<h2>Upload CSV File</h2>
<p>Select a CSV file with x, y coordinates to display on the map</p>
<input type="file" id="file-input" accept=".csv">
</div>
</div>
<!-- Insert HTML division tag to layout the map -->
<div id="map"></div>
<!-- Insert Javascript (.js) code to create the map -->
<script>
var map, controlLayers;
// Handle file upload
document.getElementById('file-input').addEventListener('change', function(e) {
var file = e.target.files[0];
if (!file) return;
// Hide upload interface, show map
document.getElementById('upload-container').style.display = 'none';
document.getElementById('map').style.display = 'block';
// Initialize map
map = L.map('map', {
center: [41.57, -72.69],
zoom: 9,
scrollWheelZoom: false,
tap: false
});
/* Control panel to display map layers */
controlLayers = L.control.layers( null, null, {
position: "topright",
collapsed: false
}).addTo(map);
// display Carto basemap tiles with light features and labels
var light = L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png', {
attribution: '&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a>, &copy; <a href="https://carto.com/attribution">CARTO</a>'
}).addTo(map);
controlLayers.addBaseLayer(light, 'Carto Light basemap');
/* Stamen colored terrain basemap tiles with labels */
var terrain = L.tileLayer('https://stamen-tiles.a.ssl.fastly.net/terrain/{z}/{x}/{y}.png', {
attribution: 'Map tiles by <a href="http://stamen.com">Stamen Design</a>, under <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>. Data by <a href="http://openstreetmap.org">OpenStreetMap</a>, under <a href="http://www.openstreetmap.org/copyright">ODbL</a>.'
});
controlLayers.addBaseLayer(terrain, 'Stamen Terrain basemap');
// Read the uploaded CSV file
var reader = new FileReader();
reader.onload = function(event) {
var csvString = event.target.result;
// Use PapaParse to convert string to array of objects
var data = Papa.parse(csvString, {header: true, dynamicTyping: true}).data;
// For each row in data, create a marker and add it to the map
for (var i in data) {
var row = data[i];
var marker = L.marker([row.Latitude, row.Longitude], {
opacity: 1
}).bindPopup(row.Title);
marker.addTo(map);
}
};
reader.readAsText(file);
});
</script>
</body>
</html>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment