freeuamap.js

/*global $,map*/
$(document).ready(function () {
    var button = document.querySelector('.gotoothermap');
    var originalMapLayer;
    map.eachLayer(function (layer) {
        if (!originalMapLayer &&
            layer._url &&
            layer._url.indexOf('maps.liveuamap.com/osm_tiles/') !== -1) {
            originalMapLayer = layer;
        }
    });

    var esriWorld = L.tileLayer('https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}', {
        attribution: 'Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, UPR-EGP, and the GIS User Community'
    });

    var esriNatGeoWorldMap = L.tileLayer('https://server.arcgisonline.com/ArcGIS/rest/services/NatGeo_World_Map/MapServer/tile/{z}/{y}/{x}', {
        attribution: 'Tiles © Esri — National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, iPC',
        maxZoom: 16
    });

    var openTopoMap = L.tileLayer('https://{s}.tile.opentopomap.org/{z}/{x}/{y}.png', {
        maxZoom: 17,
        attribution: 'Map data: &copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a>, <a href="http://viewfinderpanoramas.org">SRTM</a> | Map style: &copy; <a href="https://opentopomap.org">OpenTopoMap</a> (<a href="https://creativecommons.org/licenses/by-sa/3.0/">CC-BY-SA</a>)'
    });

    var NASAGIBS_ViirsEarthAtNight2012 = L.tileLayer('https://map1.vis.earthdata.nasa.gov/wmts-webmerc/VIIRS_CityLights_2012/default/{time}/{tilematrixset}{maxZoom}/{z}/{y}/{x}.{format}', {
        attribution: 'Imagery provided by services from the Global Imagery Browse Services (GIBS), operated by the NASA/GSFC/Earth Science Data and Information System (<a href="https://earthdata.nasa.gov">ESDIS</a>) with funding provided by NASA/HQ.',
        bounds: [[-85.0511287776, -179.999999975], [85.0511287776, 179.999999975]],
        minZoom: 1,
        maxZoom: 8,
        format: 'jpg',
        time: '',
        tilematrixset: 'GoogleMapsCompatible_Level'
    });

    var layers = [originalMapLayer,
        esriWorld,
        esriNatGeoWorldMap,
        openTopoMap,
        NASAGIBS_ViirsEarthAtNight2012];

    var activeIndex = 0;

    button.onclick = function (event) {
        event.preventDefault();
        map.removeLayer(layers[activeIndex]);
        activeIndex = (activeIndex + 1) % layers.length;
        map.addLayer(layers[activeIndex]);
        return false;
    };
});