Usage

Layer options
Coordinate reference systems (CRS)
Utility functions

Layer options

A map layer from this plugin is created like this:

var swissLayer = L.tileLayer.swiss(/* options */);

// The layer also needs to be added to a map
swissLayer.addTo(map);

If you do not pass any options, you get the default base map layer:

var baseMapLayer = L.tileLayer.swiss();

Swisstopo offers many other layers in addition to the default base map.

// Satellite image layer
var satelliteLayer = L.tileLayer.swiss({
  layer: 'ch.swisstopo.swissimage',
  maxNativeZoom: 28
});

// Cycling route overlay
var cyclingOverlay = L.tileLayer.swiss({
  format: 'png',
  layer: 'ch.astra.veloland',
  maxNativeZoom: 26,
  opacity: 0.5
});

// Historic base map from the year 2010
var historicMap2010 = L.tileLayer.swiss({
  format: 'png',
  layer: 'ch.swisstopo.zeitreihen',
  maxNativeZoom: 26,
  timestamp: '20101231'
});

Note that options must correspond to what is available on Swisstopo servers, e.g. if you specify format: 'jpeg' for the historic base map, it will not work. See layer list to find correct combinations of options.

Overview of all available options with their default values:

L.tileLayer.swiss({
  // Attribution. The required attribution to Swisstopo is added by default.
  attribution: '© <a href="https://www.swisstopo.ch/">Swisstopo</a>',
  // Coordinate reference system. EPSG2056 and EPSG21781 are available.
  crs: L.CRS.EPSG2056
  // Image format (jpeg or png). Only one format is available per layer.
  format: 'jpeg',
  // Layer name.
  layer: 'ch.swisstopo.pixelkarte-farbe',
  // Minimum zoom. Levels below 14 exist for technical reasons,
  // but you probably do not want to use them.
  minZoom: 14,
  // Maximum zoom. Availability of zoom levels depends on the layer.
  maxNativeZoom: 27,
  // Plugin attribution. Display a small Swiss flag with a link to this plugin. 🇨🇭
  // (Like the "🇺🇦 Leaflet" prefix, this is enabled by default but not required)
  pluginAttribution: true,
  // Timestamp. Most (but not all) layers have a 'current' timestamp.
  // Some layers have multiple versions with different timestamps.
  timestamp: 'current',
  // Map tile URL. Appropriate defaults are chosen based on the crs option.
  url: 'https://wmts{s}.geo.admin.ch/1.0.0/{layer}/default/{timestamp}/2056/{z}/{x}/{y}.{format}'
});

Coordinate reference systems (CRS)

LV95 is the new reference frame used in Switzerland since 2016. LV95 coordinates are by convention designated by the letters E for the easting and N for the northing, with origin at E = 2 600 000 m / N = 1 200 000 m. The origin is not at 0 / 0 to avoid confusion between easting and northing, this is sometimes called “false easting” and “false northing”.

LV95 is the CRS in which Swiss maps are currently produced, and is the default for this plugin. While it is technically possible to reproject maps to another CRS, this always involves changes in scale and/or rotation and decreases the quality of the map.

Leaflet uses EPSG codes to refer to CRS. This plugin adds LV95 as a Leaflet CRS:

L.CRS.EPSG2056;

Leaflet always uses geographic coordinates, aka latitude and longitude to refer to points on the map.

If you already know the geographic coordinates of your points, you can use them directly:

// Add a marker in Zurich
L.marker([47.378, 8.538]).addTo(map);

// Center the map on Bern
map.setView([46.951, 7.439], 20);

If your points are in LV95, they have to be transformed to geographic coordinates first by creating a Leaflet Point and calling unproject():

// Add a marker in Zurich
L.marker(L.CRS.EPSG2056.unproject(L.point(2683000, 1248000))).addTo(map);

// Center the map on Bern
map.setView(L.CRS.EPSG2056.unproject(L.point(2600000, 1200000)), 20);

If you receive coordinates from Leaflet, e.g. from a click event, you will also get geographic coordinates. Call project() to transform them to LV95. Note that it returns a Leaflet Point, so coordinates have to be accessed using the x and y attributes:

map.on('click', function (event) {
  var latlng = event.latlng;
  var EN = L.CRS.EPSG2056.project(latlng);
  console.log('Clicked on (lat/lng): ' + latlng.lat + '/' + latlng.lng);
  console.log('Clicked on (E/N): ' + EN.x + '/' + EN.y);
});

The old Swiss CRS, LV03 (EPSG code 21781), is also added by this plugin. You will probably not need this:

L.CRS.EPSG21781;

Utility functions

This plugin adds a convenience function to the Leaflet Map interface to set the map view, such that the entire country is visible.

map.fitSwitzerland();