layers.js

// -*- mode: javascript; indent-tabs-mode: nil; c-basic-offset: 8 -*-
"use strict";

// Base layers configuration

function createBaseLayers() {
        var layers = [];

        var world = [];
        var us = [];

        world.push(new ol.layer.Tile({
                source: new ol.source.OSM(),
                name: 'osm',
                title: 'OpenStreetMap',
                type: 'base',
        }));

        if (BingMapsAPIKey) {
                world.push(new ol.layer.Tile({
                        source: new ol.source.BingMaps({
                                key: BingMapsAPIKey,
                                imagerySet: 'Aerial'
                        }),
                        name: 'bing_aerial',
                        title: 'Bing Aerial',
                        type: 'base',
                }));
                world.push(new ol.layer.Tile({
                        source: new ol.source.BingMaps({
                                key: BingMapsAPIKey,
                                imagerySet: 'Road'
                        }),
                        name: 'bing_roads',
                        title: 'Bing Roads',
                        type: 'base',
                }));
        }

        if (ChartBundleLayers) {
                var chartbundleTypes = {
                        sec: "Sectional Charts",
                        tac: "Terminal Area Charts",
                        hel: "Helicopter Charts",
                        enrl: "IFR Enroute Low Charts",
                        enra: "IFR Area Charts",
                        enrh: "IFR Enroute High Charts"
                };

                for (var type in chartbundleTypes) {
                        us.push(new ol.layer.Tile({
                                source: new ol.source.TileWMS({
                                        url: 'http://wms.chartbundle.com/wms',
                                        params: {LAYERS: type},
                                        projection: 'EPSG:3857',
                                        attributions: 'Tiles courtesy of <a href="http://www.chartbundle.com/">ChartBundle</a>'
                                }),
                                name: 'chartbundle_' + type,
                                title: chartbundleTypes[type],
                                type: 'base',
                                group: 'chartbundle'}));
                }
        }

        var nexrad = new ol.layer.Tile({
                name: 'nexrad',
                title: 'NEXRAD',
                type: 'overlay',
                opacity: 0.5,
                visible: false
        });
        us.push(nexrad);

        var refreshNexrad = function() {
                // re-build the source to force a refresh of the nexrad tiles
                var now = new Date().getTime();
                nexrad.setSource(new ol.source.XYZ({
                        url : 'http://mesonet{1-3}.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913/{z}/{x}/{y}.png?_=' + now,
                        attributions: 'NEXRAD courtesy of <a href="http://mesonet.agron.iastate.edu/">IEM</a>'
                }));
        };

        refreshNexrad();
        window.setInterval(refreshNexrad, 5 * 60000);

        if (world.length > 0) {
                layers.push(new ol.layer.Group({
                        name: 'world',
                        title: 'Worldwide',
                        layers: world
                }));
        }

        if (us.length > 0) {
                layers.push(new ol.layer.Group({
                        name: 'us',
                        title: 'US',
                        layers: us
                }));
        }

        return layers;
}