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<!DOCTYPE html>
<html lang="en-GB">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no"/>
<meta charset="UTF-8"/>
<meta name="keywords" content="explore, map, mapping, interactive, spatial, trafford, leaflet, leafletjs, geojson, data"/>
<meta name="description" content="Explore the different assets, facilities and areas within the borough of Trafford."/>
<title>Trafford Data Lab: Explore</title>
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.3.1/dist/leaflet.css" integrity="sha512-Rksm5RenBEKSKFjgI3a41vrjkw4EVPlJ3+OiI65vTjIdo9brlAacEuKOiQ5OFh7cOI1bkDwLqdLw3Zg0cRJAAQ==" crossorigin=""/>
<link rel="stylesheet" href="https://unpkg.com/leaflet.markercluster@1.3.0/dist/MarkerCluster.css"/>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/MarkerCluster.TraffordDataLab.min.css"/>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css"/>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans%7CRoboto"/>
<link rel="stylesheet" href="https://www.trafforddatalab.io/css/labBase.css"/>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/labLeafletMap.min.css"/>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/trafforddatalab/leaflet.reachability@v2.0.1/leaflet.reachability.min.css"/>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/leaflet.reachability_lab.min.css"/>
<link rel="stylesheet" href="https://api.tiles.mapbox.com/mapbox-gl-js/v0.52.0/mapbox-gl.css"/>
<style>
.aboutContainer
{
margin-bottom: 10px;
}
.infoDockContainer
{
max-height: 250px;
}
.propertiesTable
{
width: 100%;
font-size: 12px;
background-color: rgba(240,240,240,0.5);
}
.propertiesTable td
{
vertical-align: top;
border-bottom: 1px dotted #ccc;
}
.propertiesTable td:nth-child(1)
{
font-weight: bold;
width: 1%;
white-space: nowrap;
}
.datasetSelect
{
width: 100%;
}
@media (min-width:621px)
{
.mainPanelControl
{
width: 280px; /* desired width when not on mobiles */
}
}
.toggleCluster
{
font-size: 12px;
}
.shareButton
{
padding-right: 9px;
}
.shareButtonActive
{
color: #fc6721;
}
</style>
</head>
<body>
<div id="map" class="mapFullScreen">
<input type="text" id="shareUrl" contenteditable="true" readonly="false" style="width: 1px; height: 1px; border: 0; left: -333px; top: -333px;"/>
</div>
<script src="https://unpkg.com/leaflet@1.3.1/dist/leaflet.js" integrity="sha512-/Nsx9X4HebavoBvEBuyp3I7od5tA0UzAxs+j83KgC8PU0kgB4XiK4Lfe4y4cgBtaRJQEIFCW+oC506aPT2L1zw==" crossorigin=""></script>
<script src="https://cdn.jsdelivr.net/npm/leaflet.locatecontrol@0.62.0/dist/L.Control.Locate.min.js"></script>
<script src="https://unpkg.com/leaflet.markercluster@1.3.0/dist/leaflet.markercluster.js"></script>
<script src="https://api.tiles.mapbox.com/mapbox-gl-js/v0.52.0/mapbox-gl.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/mapbox-gl-leaflet@error_handler/leaflet-mapbox-gl.min.js"></script>
<script src="https://www.trafforddatalab.io/assets/javascript/labError.js"></script>
<script src="https://www.trafforddatalab.io/assets/javascript/labAjax.js"></script>
<script src="https://www.trafforddatalab.io/assets/javascript/labGetQryStrValByKey.js"></script>
<script src="https://www.trafforddatalab.io/assets/javascript/labSpinner.js"></script>
<script src="https://www.trafforddatalab.io/assets/javascript/changeLuminosity.js"></script>
<script src="https://www.trafforddatalab.io/assets/javascript/supportWebGL.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/labMarkerSVG.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/labCreateTileLayer.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/labCreateVectorTileLayer.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/labLeafletMap.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/lab_leaflet@v1.1.1/leaflet.reachability_lab_setup.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/trafforddatalab/leaflet.reachability@v2.0.1/leaflet.reachability.min.js"></script>
<script>
// 2019-07-11: For compatibility with URLs containing a QueryString to specify a dataset, (e.g. https://www.trafforddatalab.io/explore/?dataset=libraries) the following replaces it for a hash causing the page to reload.
// In most circumstances this should go unnoticed. The new method uses hashes to record map state as this allows the url to be updated without reloading the page.
if (location.href.indexOf('?') > -1) location.href = location.href.replace('?', '#');
// ######### FUNCTIONS #########
// To setup each feature within GeoJSON
function featureEvents (feature, layer) {
// we need to discover the feature type - remember it is valid for this to be null!
if (feature.hasOwnProperty('type')) {
featureType = feature.type.toLowerCase();
if (featureType == 'feature' || featureType == 'featurecollection') {
if (feature.hasOwnProperty('geometry') && feature.geometry.hasOwnProperty('type')) featureType = (feature.geometry.type !== null) ? feature.geometry.type.toLowerCase() : null;
}
}
// based on the feature type we now need to set the correct layer type
if (featureType == 'point' && feature.hasOwnProperty('properties') && feature.properties.hasOwnProperty('featureRadius') && feature.properties.featureRadius !== '') {
layer.type = 'circle'; // special case as there is no circle in GeoJSON - therefore we can only distinguish between a circle and a point if we have a radius value
}
else if (featureType == 'point' || featureType == 'multipoint') {
layer.type = 'marker';
// For this type of layer we also want to store the colour and the size of the marker
// If the information is not present use defaults of medium and Lab orange
layer.markerColour = (feature.hasOwnProperty('properties') && feature.properties.hasOwnProperty('marker-color')) ? feature.properties['marker-color'] : '#fc6721';
layer.markerSize = (feature.hasOwnProperty('properties') && feature.properties.hasOwnProperty('marker-size')) ? feature.properties['marker-size'] : 'medium';
}
else if (featureType == 'polygon' || featureType == 'multipolygon') {
layer.type = 'polygon';
}
else if (featureType == 'linestring' || featureType == 'multilinestring') {
layer.type = 'polyline';
}
else {
layer.type = featureType; // probably null
}
// Add handler to layer to show properties onclick
layer.on({
click: showLayerProps
});
}
// This function is for styling non-point data. If it has internal styling properties use them, otherwise use a default
function styleOverlayData(feature) {
var styles = {
color: '#fc6721',
fillColor: '#fc6721',
opacity: 0.5,
fillOpacity: 0.2
};
var props = feature.properties;
if (props != null) {
if (props['stroke'] != null) styles['color'] = props['stroke'];
if (props['stroke-width'] != null) styles['weight'] = props['stroke-width'];
if (props['stroke-opacity'] != null) styles['opacity'] = props['stroke-opacity'];
if (props['fill'] != null) styles['fillColor'] = props['fill'];
if (props['fill-opacity'] != null) styles['fillOpacity'] = props['fill-opacity'];
}
return styles;
}
// To setup any point data features within GeoJSON
function pointData (feature, latlng) {
if (labMap.datasetCluster == null) {
// create the marker cluster object in case we require this feature - also indicates to the application that we have point data in the dataset
labMap.datasetCluster = L.markerClusterGroup({
spiderLegPolylineOptions: { weight: 2, color: '#fc6721', opacity: 0.5 },
polygonOptions: { weight: 2, color: '#fc6721', opacity: 0.5, dashArray: '5' }
});
}
if (feature.hasOwnProperty('properties') && feature.properties.hasOwnProperty('featureRadius') && feature.properties.featureRadius !== '') {
// create a circle marker as we have a radius property value
return L.circle(latlng, { radius: feature.properties.featureRadius });
}
else {
// get the colour and size information if available from the properties object, otherwise use defaults
var markerColour = (feature.hasOwnProperty('properties') && feature.properties.hasOwnProperty('marker-color')) ? feature.properties['marker-color'] : '#fc6721';
var markerSize = (feature.hasOwnProperty('properties') && feature.properties.hasOwnProperty('marker-size')) ? feature.properties['marker-size'] : 'medium';
return L.marker(latlng, { icon: labMarkerSVG({
color: markerColour,
size: markerSize
})
});
}
}
// Reset the styling of a previously selected feature
function resetFeatureStyle() {
if (labMap.featureCache != null) {
var layer = labMap.featureCache;
if (layer.type == 'marker') {
// Specific reset implementation for markers
layer.setIcon(labMarkerSVG({
color: layer.markerColour,
size: layer.markerSize
})
);
}
else if (isDatasetLayer(layer)) {
// The feature belongs to a dataset that has been loaded
labMap.datasetGeoJson.resetStyle(layer);
}
else if (isIsolineLayer(layer)) {
// The feature is an isoline drawn with the reachability plugin
labMap.reachabilityControl.isolinesGroup.resetStyle(layer);
}
else {
// The feature is a polygon from a geography boundary. Easier to just set the style back to the default than resetting it via the L.geoJSON method
layer.setStyle(labMap.poly);
}
labMap.featureCache = null; // clear the cache to prevent a situation where no feature is currently selected but the cache still contains the previously selected layer
}
}
// Show the properties of a selected layer
function showLayerProps(e) {
L.DomEvent.stopPropagation(e); // stop the event bubbling to the map which would cause the information to be removed from the info panel etc.
var layer = e.target;
var propsTable = '';
// Find out what type of layer this is
var isReachability = isIsolineLayer(layer);
var isGeography = isGeographyLayer(layer);
var isDataset = isDatasetLayer(layer);
// reset the style of a previously selected feature
resetFeatureStyle();
// add new selected feature to the cache
labMap.featureCache = layer;
// set the highlight style of the selected feature
if (layer.type == 'marker') {
layer.setIcon(labMarkerSVG({
color: '#ffea00',
size: layer.markerSize
})
);
}
else {
layer.setStyle(labMap.polySelected);
/*
Do we want to bring this layer to the front? If it's a boundary geography definitely yes as they often have overlapping lines. When we select one, we want the whole outline to be on top as it is highlighted in yellow, not have parts hidden under the black lines of neighbouring boundaries. The same is true for certain datasets like the Agricultural land. However, with reachability isolines, the user wouldn't be able to select the smaller intervals once they'd selected a larger one if the layers reordered, as the larger one would be covering the smaller layer(s). The same is also true for certain other layered datasets like OS Greenspaces which have smaller polygons layered on top of larger ones and the ordering needs to be preserved.
So, how to handle this? Only bring the layer to the front if belongs to a geography layer, or if it belongs to a dataset and there isn't a flag in the datasets.json telling us not to.
*/
if (isGeography || (isDataset && labMap.preventLayerToFront == false)) layer.bringToFront();
}
// build the content for the properties table to be displayed
if (layer.feature.hasOwnProperty('properties')) {
var props = layer.feature.properties;
var propsVal, prefix;
var matchIndex = 0;
var arrEmail = [];
for (var key in props) {
// Ensure that the key is a valid property of the GeoJson object and isn't one of the styling options or a reachability range/area units or measure attribute (because we deal with these later)
if (props.hasOwnProperty(key) && key != 'stroke' && key != 'stroke-width' && key != 'stroke-opacity' && key != 'fill' && key != 'fill-opacity' && key != 'marker-color' && key != 'marker-size' && !(isReachability && (key.indexOf('units') > -1 || key == 'Measure'))) {
if (props[key] === null || props[key] === undefined || props[key] !== props[key]) { // The strange test of the property value not equalling itself is for NaN as NaN, uniquely, is never equal to itself
propsVal = '';
}
else if (isNaN(props[key])) { // Given that we have screened out the possibility of props[key] being NaN, this test is to check if props[key] is numeric or not. If it's not just numeric we might want to perform some processing on it to enhance the presentation.
/*
To enhance usability turn email or web addresses found within the property value into hyperlinks. Works for single or multiple occurrences
NOTE:
- For efficiency this is done here each time the user selects a feature, rather than on the whole dataset when it is loaded. It is likely only a few features will be selected by the user.
- Not claiming to match every occurrence, but a high proportion. There will always be ones that slip through, but this is an enhancement feature rather than a validation so isn't an issue.
- The method of pushing the matching email addresses to an array, substituting an indexed string then replacing with the HTML link is done to prevent the second regex matching the domain parts of email addresses or parts of the href property etc.
- Regex obtained from: https://emailregex.com and http://urlregex.com
*/
// Find email addresses
propsVal = props[key].replace(/[a-zA-Z0-9.!#$%&’*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*/gi, function (x) {
arrEmail.push('<a href="mailto:' + x + '">' + x + '</a>');
return '@@@EMAIL' + matchIndex++ + '@@@'; // replace with a temporary placeholder to prevent the web address regex matching part of the email addresses as well
});
// Find URLs - NOTE: we need to replace the value of propsVal NOT props[key] as we might have properties with a mix of email and web addresses
propsVal = propsVal.replace(/\b(<a href=")?(http:\/\/www\.|https:\/\/www\.|http:\/\/|https:\/\/)?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?\b/gi, function (x) {
var prefix = (x.indexOf('http://') > -1 || x.indexOf('https://') > -1) ? '' : 'http://'; // if the URL doesn't contain the protocol we'll assume http://
return '<a href="' + prefix + x + '" target="_blank">' + x + '</a>';
});
// Finally replace all email addresses found
for (var i = 0; i < arrEmail.length; i++) {
propsVal = propsVal.replace('@@@EMAIL' + i + '@@@', arrEmail[i]);
}
}
else {
// Value seems to be a number
propsVal = props[key]; // set to the raw value initially
// The following are only applicable if the selected object is a reachability polygon
if (isReachability) {
switch (key) {
case 'Range':
propsVal = '0 - ' + props['Range'] + ' ' + props['Range units']; // Improves the presentation of the range information
break;
case 'Area':
propsVal = props['Area'] + ' ' + props['Area units'].replace('^2', '<sup>2</sup>'); // Improves the presentation of the area information
break;
case 'Latitude':
case 'Longitude':
propsVal = props[key].toFixed(4); // Reduce the precision of the lat/lng values to a sensible number
break
case 'Population':
propsVal = props[key].toString().replace(/\B(?=(\d{3})+(?!\d))/g, ","); // Format the population number with commas separating thousands
}
}
}
propsTable += '<tr><td>' + formatPropertyKey(key) + '</td><td>' + propsVal + '</td></tr>'; // Create a row for the property table to display the key and value
}
}
if (propsTable != '') labMap.updateInfo('<table class="propertiesTable">' + propsTable + '</table>'); // So long as we have something to display, show the completed property table
}
}
// for loading data as an overlay layer
function loadDatasetLayer(datasetKey, resetClusterQS) {
if (resetClusterQS) updateMapStateUrl('cluster', null); // remove the cluster key from the URL hash if desired - e.g. when loading the dataset from the select list we want the decision as to whether point data is clustered or not by default to be made based on the cluster flag value in datasets.json, not from the QS
// Remove any current data layer and reset the variables
if (labMap.datasetLayer !== null) {
labMap.datasetLayer.removeFrom(labMap.map);
labMap.attribution.removeAttribution(labMap.datasetGeoJson.getAttribution()); // have to remove the attribution manually due to a seeming bug in Leaflet.MarkerCluster not handling it automatically
labMap.datasetLayer = null;
labMap.datasetGeoJson = null;
labMap.datasetCluster = null;
labMap.preventLayerToFront = false; // Default behaviour for dataset layers is to bring them to the front when selected. To prevent this happening the dataset needs to have a key 'preventLayerToFront' set to true in datasets.json
// ensure the cluster checkbox is hidden
if (L.DomUtil.hasClass(labMap.toggleClusterContainer, 'hideContent') == false) L.DomUtil.addClass(labMap.toggleClusterContainer, 'hideContent');
// reset the info panel if a feature from the previous dataset was selected
if (labMap.featureCache != null && isGeographyLayer(labMap.featureCache) == false && isIsolineLayer(labMap.featureCache) == false) {
labMap.updateInfo();
labMap.featureCache = null;
}
// reset the legend panel
labMap.updateLegend();
}
// Check to see if the dataset key we've been given matches any datset objects
if (labMap.objDatasets.hasOwnProperty(datasetKey)) {
// Set the page title to match the dataset title.
document.title = 'Trafford Data Lab: ' + labMap.objDatasets[datasetKey].title;
// Update the about section
labMap.updateAbout(labMap.objDatasets[datasetKey].about);
startLabSpinner() // inform the user that something is loading
// Attempt to load GeoJSON specified in the URL
labAjax(labMap.objDatasets[datasetKey].url, function (data) {
if (data !== null && data !== '') {
try {
// set the options for the GeoJSON layer
var layerOptions = { style: styleOverlayData, onEachFeature: featureEvents, pointToLayer: pointData, pane: 'pane_data_overlay' };
if (labMap.objDatasets[datasetKey].attribution !== null) layerOptions['attribution'] = 'Data source: ' + labMap.objDatasets[datasetKey].attribution;
labMap.datasetGeoJson = L.geoJSON(data, layerOptions); // create and store the GeoJSON object
// do we have point data in the dataset?
if (labMap.datasetCluster != null) {
labMap.datasetCluster.addLayer(labMap.datasetGeoJson); // add the GeoJSON to the cluster object - point data will be clustered but polygons/lines won't
// the following is a patch for a seeming bug in Leaflet.MarkerCluster not handling the layer attribution automatically
if (labMap.objDatasets[datasetKey].attribution !== null) labMap.attribution.addAttribution('Data source: ' + labMap.objDatasets[datasetKey].attribution);
// do we want clustering on or off?
// order of precedence: 1. cluster and preventUncluster flags in datasets.json are both TRUE, 2. cluster QS value is TRUE (if loading the dataset via URL, not the select list), 3. cluster flag in datasets.json is TRUE
// preventUncluster flag is for datasets containing huge numbers of points that would crash the browser, this disables the cluster checkbox to prevent the user unclustering
var clusterFlagSet = (labMap.objDatasets[datasetKey].hasOwnProperty('cluster') && labMap.objDatasets[datasetKey].cluster === true) ? true : false;
var preventUnclusterFlagSet = (labMap.objDatasets[datasetKey].hasOwnProperty('preventUncluster') && labMap.objDatasets[datasetKey].preventUncluster === true) ? true : false;
var clusterQS = labGetQryStrValByKey('cluster', location.hash); // check if we're trying to set clustering via the querystring
if ((clusterFlagSet && preventUnclusterFlagSet) || clusterQS === 'true' || (clusterQS !== 'false' && clusterFlagSet)) {
labMap.datasetLayer = labMap.datasetCluster; // the layer we are going to add to the map is the clustered version
labMap.toggleCluster.checked = true;
}
else {
labMap.datasetLayer = labMap.datasetGeoJson; // the layer we are going to add to the map is the straight GeoJSON we loaded
labMap.toggleCluster.checked = false;
}
// now determine if we need to prevent the user from unclustering the dataset
if (clusterFlagSet && preventUnclusterFlagSet) {
labMap.toggleCluster.setAttribute("disabled", "disabled");
}
else {
labMap.toggleCluster.removeAttribute("disabled");
}
L.DomUtil.removeClass(labMap.toggleClusterContainer, 'hideContent'); // show the clustering checkbox
}
else {
labMap.datasetLayer = labMap.datasetGeoJson; // the layer we are going to add to the map is the straight GeoJSON we loaded
updateMapStateUrl('cluster', null); // ensure there is no cluster key in the URL hash
}
// add the dataset layer to the map
labMap.datasetLayer.addTo(labMap.map);
// add legend content if applicable
if (labMap.objDatasets[datasetKey].hasOwnProperty('legend') && labMap.objDatasets[datasetKey].legend != null && labMap.objDatasets[datasetKey].legend !== '') labMap.updateLegend(labMap.objDatasets[datasetKey].legend);
// update the URL with the dataset selected
updateMapStateUrl('dataset', datasetKey);
/*
Check if we want to prevent the layers within the dataset being brought to the front when selected (default is false).
Some datasets like OS Greenspaces have smaller objects overlaid on larger ones, so bringing layers to the front disrupts this and causes issues for the user (e.g. smaller objects can become unselectable behind larger ones).
*/
if (labMap.objDatasets[datasetKey].hasOwnProperty('preventLayerToFront') && labMap.objDatasets[datasetKey].preventLayerToFront === true) labMap.preventLayerToFront = true;
}
catch (e) {
labError(new LabException("Error attempting to create GeoJSON Leaflet layer: " + e.message));
}
}
else {
labError(new LabException("Couldn't find URL: " + labMap.objDatasets[datasetKey].url));
}
stopLabSpinner() // remove the spinner as the data has loaded
});
}
else {
// No dataset found so reset the map to the initial state
document.title = 'Trafford Data Lab: ' + labMap.title
labMap.updateAbout(labMap.about);
updateMapStateUrl('dataset', null); // remove the dataset key from the URL hash
updateMapStateUrl('cluster', null); // remove the cluster key from the URL hash
}
}
// Handles clustering and de-clustering of point data - called via click event on clustering checkbox
function toggleClustering() {
labMap.datasetLayer.removeFrom(labMap.map);
if (document.getElementById('toggleClustering').checked) {
labMap.datasetLayer = labMap.datasetCluster; // the layer we are going to add to the map is the clustered version
updateMapStateUrl('cluster', 'true');
}
else {
labMap.datasetLayer = labMap.datasetGeoJson; // the layer we are going to add to the map is the straight GeoJSON we loaded
updateMapStateUrl('cluster', 'false'); // update the URL hash to reflect that the user has specifically removed the clustering
}
labMap.datasetLayer.addTo(labMap.map);
}
// Determines whether the layer provided is an isoline - created by the reachability plugin
function isIsolineLayer(layer) {
if (labMap.reachabilityControl != null && labMap.reachabilityControl.isolinesGroup != null) {
/*
The following iteration is seemingly required as the expected code: labMap.reachabilityControl.isolinesGroup.hasLayer(layer) doesn't work.
Each isoline or set of isolines (if intervals were created) are added to .isolinesGroup as a L.geoJSON object, thus they are effectively sub groups of .isolinesGroup.
The loop iterates through each sub group and checks if the layer is present. If so we stop checking.
*/
var arrGroups = labMap.reachabilityControl.isolinesGroup.getLayers();
for (var i = 0; i < arrGroups.length; i++) {
if (arrGroups[i].hasLayer(layer)) return true;
}
}
return false;
}
// Determines whether the layer provided is a geography boundary
function isGeographyLayer(layer) {
for (key in labMap.objGeographies) {
if (labMap.objGeographies[key].hasLayer(layer)) return true;
}
return false;
}
// Determines whether the layer provided is a dataset layer
function isDatasetLayer(layer) {
return (labMap.datasetLayer != null && labMap.datasetLayer.hasLayer(layer));
}
// Function to format the property keys of a given dataset, e.g. makes "area_name" into "Area name" so that it looks nice in the info panel
function formatPropertyKey(key) {
key = key.replace(/_/g, " "); // remove and underscore characters and replace with spaces
return key.substring(0, 1).toUpperCase() + key.substring(1); // capitalise the first character and then return the result
}
// Error functions for vector tile layers
/*
The error event is fired by mapbox-gl.js and listened for in leaflet-mapbox-gl.js.
From there the error function specified in the options parameter of the L.mapboxGL object is called.
At this point the layer has already been created and added to the map, hence why in the functions below the layer is first removed from the map and destroyed before the alternative is created.
This is due to the difference in the way vector tiles and raster tiles are instantiated.
*/
function vectorTileErrorZoomstackLight(e) {
labMap.baseLayers.Light.removeFrom(labMap.map);
labMap.baseLayers.Light = labCreateTileLayer('CartoDB.Positron');
labMap.baseLayers.Light.addTo(labMap.map);
labMap.updateLayerControl();
}
function vectorTileErrorZoomstackOutdoor(e) {
labMap.baseLayers.Outdoor.removeFrom(labMap.map);
labMap.baseLayers.Outdoor = labCreateTileLayer('OpenStreetMap.Hot');
labMap.baseLayers.Outdoor.addTo(labMap.map);
labMap.updateLayerControl();
}
function vectorTileErrorZoomstackRoad(e) {
labMap.baseLayers.Road.removeFrom(labMap.map);
labMap.baseLayers.Road = labCreateTileLayer('OpenStreetMap.Mapnik');
labMap.baseLayers.Road.addTo(labMap.map);
labMap.updateLayerControl();
}
// Updates the hash component of the URL with dataset, zoom and latlng coordinates key/value pairs in order to allow users to share the current state of the map
function updateMapStateUrl(key, value) {
var zoom, latlng, dataset, cluster;
zoom = (key == 'zoom') ? value : getZoomHash();
latlng = (key == 'latlng') ? value : getLatLngHash();
dataset = (key == 'dataset') ? value : getDatasetHash();
cluster = (key == 'cluster') ? value : getClusterHash();
var newHash = '';
if (zoom != null) newHash = 'zoom=' + zoom;
if (latlng != null) {
if (newHash != '') newHash += '&';
newHash += 'latlng=' + latlng;
}
if (dataset != null) {
if (newHash != '') newHash += '&';
newHash += 'dataset=' + dataset;
}
if (cluster != null) {
if (newHash != '') newHash += '&';
newHash += 'cluster=' + cluster;
}
location.hash = newHash;
// Update the URL in the hidden text field for the share button
var shareUrl = document.getElementById("shareUrl");
shareUrl.value = location.href;
L.DomUtil.addClass(labMap.shareBtn, 'shareButtonActive'); // Make the share button orange again to indicate that the URL has changed
}
// Obtains the value of the zoom passed via the URL hash
function getZoomHash() {
var zoom = parseFloat(labGetQryStrValByKey('zoom', location.hash));
// Zoom value must be a number between the minimum and maximum defined when the labMap object is initialised
return (isNaN(zoom) == false && zoom >= labMap.attributes.minZoom && zoom <= labMap.attributes.maxZoom) ? zoom : null;
}
// Obtains the value of the latlng passed via the URL hash
function getLatLngHash() {
return labGetQryStrValByKey('latlng', location.hash);
}
// Obtains the value of the dataset passed via the URL hash
function getDatasetHash() {
return labGetQryStrValByKey('dataset', location.hash);
}
// Obtains the value of the cluster state (of point data only) passed via the URL hash
function getClusterHash() {
return labGetQryStrValByKey('cluster', location.hash);
}
// ######### INITIALISATION #########
// Set up the basic map environment
var labMap = new LabLeafletMap({
title: 'Explore',
about: 'Discover the different geographies within Trafford by choosing a layer <img src="https://unpkg.com/leaflet@1.9.4/dist/images/layers-2x.png" alt="Layers menu icon" style="width: 20px; vertical-align: bottom;"/> and then selecting an area. Visualise datasets from the following selection.',
aboutToggle: 1, // Expand the panel by default as I think people are missing the content within, i.e. the downloads
baseLayers: {}, // Override the default baselayers in LabMap so that we can use OS Zoomstack vector layers if possible
attributes: { // Override the default attributes in LabMap so that we can specify the maxBounds - the OS Zoomstack vector layers only cover Great Britain
center: [53.4189, -2.33],
zoom: 12,
minZoom: 10,
maxZoom: 18,
zoomDelta: 0.25,
zoomSnap: 0,
maxBounds: [[ 49.84 , -8.74 ], [ 60.9, 1.96 ]] // fix map view to the extent of Great Britain
}
});
// legend toggle button
labMap.shareBtn = document.createElement('div'); // creating the toggle button..
labMap.shareBtn.setAttribute('title', 'Share - copy map link to clipboard'); // ..add the tooltip..
labMap.shareBtn.setAttribute('class', 'fa fa-share-alt-square toggleGadget shareButton shareButtonActive'); // ..the CSS..
labMap.shareBtn.addEventListener('click', function () { // ..and the click event..
try {
// Copy the URL to the clipboard from the text box element
var shareUrl = document.getElementById("shareUrl");
shareUrl.select(); // try to select the content of the text box...
shareUrl.setSelectionRange(0, shareUrl.value.length); // ...but use this if the browser doesn't support .select() (mainly iOS devices)
document.execCommand("copy");
}
catch(e) {
// The copy to clipboard failed so show message instead
alert('Please copy the URL in the address bar to share this map.');
}
L.DomUtil.removeClass(labMap.shareBtn, 'shareButtonActive');
});
labMap.titleContainer.appendChild(labMap.shareBtn);
if (supportWebGL()) {
/*
Attempt to create vector tile base layers.
If an error occurs we fallback to using raster tile layers (and they have built in fallback in case the tile URL can't be loaded).
*/
labMap.baseLayers = {
'Light': labCreateVectorTileLayer('OSZoomstack.Light'),
'Outdoor': labCreateVectorTileLayer('OSZoomstack.Outdoor'),
'Road': labCreateVectorTileLayer('OSZoomstack.Road'),
'White': labCreateTileLayer(null)
}
}
else {
// Fallback to use raster tile layers instead of vector.
labMap.baseLayers = {
'Light': labCreateTileLayer('CartoDB.Positron'),
'Outdoor': labCreateTileLayer('OpenStreetMap.Hot'),
'Road': labCreateTileLayer('OpenStreetMap.Mapnik'),
'White': labCreateTileLayer(null)
}
}
labMap.updateLayerControl(); // update the layer control with the raster tile layers
labMap.baseLayers.Light.addTo(labMap.map); // choose the initial base/tile layer for the map
// Add the isochrones plugin
labMap.reachabilityControl = labSetupReachabilityPlugin({
// Common options are taken care of in the function, however the options below are extra
styleFn: labStyleIsolines,
clickFn: showLayerProps,
pane: 'pane_geography_overlay',
attributes: '"area","total_pop"'
});
labMap.reachabilityControl.addTo(labMap.map);
labMap.datasetGeoJson = null; // object to store GeoJSON created from datasets loaded from the select list. ***NOTE*** this object is important for the resetting of styles for clusered marker datasets
labMap.datasetCluster = null; // object to store a leaflet.markercluster object - created if the dataset contains point data
labMap.datasetLayer = null; // either a copy of labMap.datasetGeoJson or labMap.datasetCluster containing labMap.datasetGeoJson layers - depends on whether we are clustering point data or not
labMap.featureCache = null; // for caching the currently selected feature
// Polygon feature styling
labMap.poly = {
color: '#212121',
weight: 2,
fillOpacity: 0
};
// Selected polygon styling
labMap.polySelected = {
color: '#ffea00',
weight: 5,
opacity: '1'
};
// ######### EVENTS #########
// Reset the map state if any features have been selected
labMap.map.on('click', (function (e) {
resetFeatureStyle(); // reset the style of a previously selected feature
labMap.updateInfo(); // clear and hide the info panel
}));
labMap.map.on('reachability:api_call_start', function (e) {
// indicate to the user that something is happening at the start of the API call
startLabSpinner();
});
labMap.map.on('reachability:api_call_end', function (e) {
// stop the spinner at the end of the API call
stopLabSpinner();
});
labMap.map.on('reachability:delete', function (e) {
// Check that the recently deleted isoline wasn't currently selected
if (labMap.featureCache != null) {
var layer = labMap.featureCache;
if (isIsolineLayer(layer) == false && isGeographyLayer(layer) == false && isDatasetLayer(layer) == false) {
// The currently cached layer must've been an isoline which has now been deleted so reset the info panel and cache
labMap.updateInfo();
labMap.featureCache = null;
}
}
});
labMap.map.on('zoomend', function (e) {
// Update the URL with the new zoom level
updateMapStateUrl('zoom', labMap.map.getZoom());
});
labMap.map.on('moveend', function (e) {
// Get the new centre coordinate of the map
var mapCentre = labMap.map.getCenter();
// Update the URL with the new latlng
updateMapStateUrl('latlng', encodeURIComponent(mapCentre.lat + ' ' + mapCentre.lng));
});
// ######### DATASET METADATA & SELECTION UI #########
labAjax('datasets.json', function (data) {
// Load the JSON holding the metadata for all the datasets which we can visualise in Explore, in the form:
/*
"": {
"title": "",
"about": "",
"attribution": "",
"url": "",
"theme": "",
"cluster": true, // OPTIONAL
"hidden": true, // OPTIONAL
"legend": "" // OPTIONAL
}
*/
labMap.objDatasets = data; // store the dataset data
var arrSelectList = []; // array to hold the contents of the select list to choose the dataset to visualise
// Loop through the labMap.objDatasets object adding the main key, title and theme to the array so long as the key is a dataset and we don't want it hidden
for (key in labMap.objDatasets) {
if (labMap.objDatasets.hasOwnProperty(key) && (!labMap.objDatasets[key].hasOwnProperty('hidden') || (labMap.objDatasets[key].hasOwnProperty('hidden') && labMap.objDatasets[key].hidden !== true))) {
arrSelectList.push({ dataset: key, title: labMap.objDatasets[key].title, theme: labMap.objDatasets[key].theme });
}
}
// Sort the select list array by the themes first as these form the optgroup headings, then by the dataset titles
arrSelectList.sort(function(a, b) {
var themeA = a.theme.toLowerCase();
var themeB = b.theme.toLowerCase();
var titleA = a.title.toLowerCase();
var titleB = b.title.toLowerCase();
// attempt sorting by theme first
if (themeA < themeB) return -1;
if (themeA > themeB) return 1;
// if the theme is the same, sort by the title
if (titleA < titleB) return -1;
if (titleA > titleB) return 1;
return 0;
});
// Check the URL for a dataset key in the URL
var datasetQS = getDatasetHash();
// Create the select element to choose the labMap.objDatasets
var datasetSelect = '<select name="frmDatasetList" onChange="loadDatasetLayer(this.value, true)" class="datasetSelect"><option value="" selected="selected">Select a dataset to visualise...</option>';
var optGroupTheme = ''; // ensure we create new optgroup tags based on the themes
for (var i = 0; i < arrSelectList.length; i++) {
// Write out new optgroup tag
if (optGroupTheme != arrSelectList[i].theme) {
if (optGroupTheme != '') datasetSelect += '</optgroup>';
datasetSelect += '<optgroup label="' + arrSelectList[i].theme + '">';
optGroupTheme = arrSelectList[i].theme;
}
// Write out the dataset list
datasetSelect += '<option value="' + arrSelectList[i].dataset + '"';
if (datasetQS == arrSelectList[i].dataset) datasetSelect += ' selected="selected"';
datasetSelect += '>' + arrSelectList[i].title + '</option>';
}
datasetSelect += '</optgroup></select>';
// Add the dataset chooser UI to the filter container along with the element to toggle point data clustering
labMap.updateFilterGUI(datasetSelect + '<div id="toggleClusteringContainer" class="hideContent"><input type="checkbox" id="toggleClustering" onClick="toggleClustering()"/><label for="toggleClustering" class="toggleCluster">cluster markers</label></div>');
// Store a reference to the checkbox and container for the point data clustering control so that we can show/hide by adding or removing a CSS class, check/uncheck it etc.
labMap.toggleCluster = document.getElementById('toggleClustering');
labMap.toggleClusterContainer = document.getElementById('toggleClusteringContainer');
// If a dataset has been specified via the QueryString, attempt to load it
if (datasetQS !== null) loadDatasetLayer(datasetQS, false);
});
// ######### SPATIAL GEOGRAPHY LAYERS/LABELS #########
labMap.objGeographies = {}; // object to hold all the boundary L.geoJSON objects so that we can test in a loop for which layer belongs to which geography
// Add the Trafford boundary
labAjax('https://www.trafforddatalab.io/spatial_data/local_authority/2023/trafford_local_authority_full_resolution.geojson', function (data) {
labMap.objGeographies['LA'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents }).addTo(labMap.map);
try {
// We need to see if we have a zoom and latlng provided in the URL - if so we need to go to that point on the map, otherwise fit to the boundary of Trafford
var zoom = getZoomHash();
var latlng = getLatLngHash();
if (zoom == null && latlng == null) {
labMap.map.fitBounds(labMap.objGeographies['LA'].getBounds()); // adjust the zoom to fit the boundary to the screen size
}
else if (zoom != null && latlng != null) {
labMap.map.setView(L.latLng(latlng.split(' ')), zoom); // zoom and move the map to the values provided in the URL hash
}
else if (zoom != null) {
labMap.map.setZoom(zoom); // zoom in to the value provided in the URL hash
}
else {
labMap.map.panTo(L.latLng(latlng.split(' '))); // move the map to the latlng provided in the URL hash
}
}
catch (e) {
// There's been a problem with the zoom or latlng values in the URL hash so just fit to bounds of Trafford
labMap.map.fitBounds(labMap.objGeographies['LA'].getBounds()); // adjust the zoom to fit the boundary to the screen size
}
labMap.overlayLayers['1. Local authority'] = labMap.objGeographies['LA'];
labMap.updateLayerControl();
});
// Add Trafford wards (which came into effect from 2023-05-04)
labAjax('https://www.trafforddatalab.io/spatial_data/ward/2023/trafford_ward_full_resolution.geojson', function (data) {
labMap.objGeographies['Ward'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents });
labMap.overlayLayers['2. Wards'] = labMap.objGeographies['Ward'];
labMap.updateLayerControl();
});
// Add Trafford localities (which came into effect from 2023-05-04)
labAjax('https://www.trafforddatalab.io/spatial_data/council_defined/2023/trafford_localities_full_resolution.geojson', function (data) {
labMap.objGeographies['Localities'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents });
labMap.overlayLayers['3. Localities'] = labMap.objGeographies['Localities'];
labMap.updateLayerControl();
});
// Add the Trafford MSOAs
labAjax('https://www.trafforddatalab.io/spatial_data/msoa/2021/trafford_msoa_full_resolution.geojson', function (data) {
labMap.objGeographies['MSOA'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents });
labMap.overlayLayers['4. MSOA'] = labMap.objGeographies['MSOA'];
labMap.updateLayerControl();
});
// Add the Trafford LSOAs
labAjax('https://www.trafforddatalab.io/spatial_data/lsoa/2021/trafford_lsoa_full_resolution.geojson', function (data) {
labMap.objGeographies['LSOA'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents });
labMap.overlayLayers['5. LSOA'] = labMap.objGeographies['LSOA'];
labMap.updateLayerControl();
});
// Add the Trafford OAs
labAjax('https://www.trafforddatalab.io/spatial_data/oa/2021/trafford_oa_full_resolution.geojson', function (data) {
labMap.objGeographies['OA'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents });
labMap.overlayLayers['6. OA'] = labMap.objGeographies['OA'];
labMap.updateLayerControl();
});
// Add the Trafford Creative Clusters
labAjax('https://www.trafforddatalab.io/spatial_data/council_defined/2026/trafford_creative_clusters_full_resolution.geojson', function (data) {
labMap.objGeographies['Creative_Clusters'] = L.geoJSON(data, { attribution: labMap.attributionOS, style: labMap.poly, onEachFeature: featureEvents });
labMap.overlayLayers['7. Creative Clusters'] = labMap.objGeographies['Creative_Clusters'];
labMap.updateLayerControl();
});
</script>
</body>
</html>