Leaflet: Pan, center, zoom map to marker location - leaflet

I'm new to Leaflet and having fun with it so far. I have an interactive map with 170 or so markers around the world. Each marker has a title in the popup. I'd also like to add a "zoom to" link inside of the popup. When the user clicks zoom to, I would like the map to center on the marker and zoom in to a certain zoom level (see image)
The markers are being generated in PHP as a marker array with the title, and lat/longs, and injected into a javascript var called "items."
for (var i = 0; i < items.length; i++) {
marker = new L.marker([items[i][1],items[i][2]])
.bindPopup(items[i][0])
.addTo(map);
}

Keep your markers in an associative array (index must be unique).
Put put a link in your popup text to call a function passing this index as argument.
In your javascript function use panTo or flyTo
Here is some pseudo code:
var markersById = {};
for (var i = 0; i < items.length; i++) {
marker = new L.marker([items[i][1],items[i][2]])
.bindPopup('Center on map')
.addTo(map);
markersById[i] = marker;
}
function centerMapOnPost(markerId) {
map.panTo(markersById[markerId].getLatLng());
}

Related

How to highlight features with same property in Leaflet

I have a map with many polygons stored in a GeoJSON file. I want to display these polygons on the map whereby polygons with the same feature 'BROAD_CATEGORY' are highlighted on mouseover on the map legend.
The only examples and documentation I have seen to do this relate to number values rather than text strings (e.g. this one).
This is my legend code for the map at the moment:
var legend = L.control({position: 'bottomright'});
legend.onAdd = function (map) {
var div = L.DomUtil.create('div', 'info legend');
labels = ['<strong>Language(s) of Origin</strong>'],
categories = ['Aboriginal clan','Action','Body part','Colour','Function of place','Historic event or place','Industry','Local estate','Nature','Other local places','Person','Place outside Australia','Portmanteau','Ship','Unknown'];
for (var i = 0; i < categories.length; i++) {
div.innerHTML +=
labels.push(
'<i class="circle" style="background:' + getColor(categories[i]) + '"></i> ' +
(categories[i] ? categories[i] : '+'));
}
div.innerHTML = labels.join('<br>');
return div;
};
legend.addTo(map);

Detecting clicks on multiple markers in mapbox

I am working with mapbox markers and I have created multiple markers as follows:
var cord = [{lng:,lat:},{lng:,lat:}]
function createMarker(){
for(var i = 0; i < cord.length; i++){
var marker = new mapboxgl.Marker({})
.setLngLat([cord[i].lng, cord[i].lat])
.addTo(map);
}
}
I wanted each marker to detect the click but I am unable to figure out how to do it?
Is it possible to detect click on each marker ?
You can add a click event handler like this:
marker.element.addEventListener('click', event => alert('click'));

marker with polyline while dragging the marker using leaflet

Hi I have connection between marker with polyline like this Image .
I am attaching a sample here.
How Can I make drag possible that when I drag the the marker with polyline.
example , If I drag the marker 3 it should also update the polyline point and where ever I put the marker 3 polyline should connect with marker 3.
I need this type of drag event that can update the polyline also when dragging the marker.
I am using leaflet for this purpose but still unable to solve the dragging logic of marker with polyline.
Here is the sample code I am using
$http.get("db/getConnectionData.php").then(function (response) {
$scope.links1 = response.data.records;
// $scope.showArrow();
angular.forEach($scope.links1, function(value, i) {
var source_panoId = $scope.links1[i].s_panoId;
var dest_panoId = $scope.links1[i].d_panoId;
var sPanoID = $scope.links1[i].sourcePano_id;
var dPpanoID = $scope.links1[i].destPano_id;
angular.forEach($scope.panoramas, function(value, index) {
if($scope.panoramas[index].panoId == source_panoId){
if($scope.links.indexOf($scope.panoramas[index])== -1){
$scope.links.push($scope.panoramas[index]);
}
var SlatLang = $scope.panoramas[index].project_latLng ;
var SLatLngArr = SlatLang.split(",");
var Slat = parseFloat(SLatLngArr[0]);
var Slang = parseFloat(SLatLngArr[1]);
var polypoint1 = [Slat, Slang];
angular.forEach($scope.panoramas, function(value, index1) {
if($scope.panoramas[index1].panoId == dest_panoId){
if($scope.links.indexOf($scope.panoramas[index1])== -1){
$scope.links.push($scope.panoramas[index1]);
}
var DlatLang = $scope.panoramas[index1].project_latLng ;
var DLatLngArr = DlatLang.split(",");
var Dlat = parseFloat(DLatLngArr[0]);
var Dlang = parseFloat(DLatLngArr[1]);
var polypoint2 = [Dlat, Dlang];
// Draw seperate polyline for each connection
polyline = L.polyline([[Slat, Slang],[Dlat, Dlang]],
{
color: 'blue',
weight: 5,
opacity: .7,
}
).addTo(map);
$scope.polycoords.push(polyline);
}
});
}
});
Here is the code that I am using to make drag of marker with polyline
angular.forEach($scope.panoramas, function(value, index4){
$scope.markers[index4].on('dragstart', function(e){
var latlngs = polyline.getLatLngs(),
latlng = $scope.markers[index4].getLatLng();
for (var i = 0; i < latlngs.length; i++) {
if (latlng.equals(latlngs[i])) {
this.polylineLatlng = i;
}
}
});//dragstart
$scope.markers[index4].on('drag', function(e){
var latlngs = polyline.getLatLngs(),
latlng = $scope.markers[index4].getLatLng();
latlngs.splice(this.polylineLatlng, 1, latlng);
polyline.setLatLngs(latlngs);
});//drag
$scope.markers[index4].on('dragend', function(e){
delete this.polylineLatlng;
});//dragEnd
});
First, when creating the marker, remember to pass the draggable option as true, like this:
var marker = L.marker(latLng, { draggable: true });
Now, check which drag event you want to attach a listener to and then call the redraw function of the polyline inside the callback, like this:
// var polyline defined somewhere
marker.on('drag', function (e) {
polyline.redraw();
});
If this doesn't work, please provide sample code so we can work around with it.
Edit
You also need to change the coordinates of the polyline, otherwise redraw will do nothing. Check out this answer on SO and see if it fits your needs.
Edit 2
You're using an array of polylines while the answer just uses one polyline which has the array of coordinates, so in your case you need to use two loops to accomplish the same task. You can make this faster and maybe use an object as a lookup table to get the right polyline for each marker, for example, like this:
var table = {};
// ...
table[marker] = polyline;
Then later you can get the polyline used for each marker. But anyway, here's what I think would work in your case the way it is in the sample (it was a little hard to understand but I hope it works for you).
I don't know where you are putting the second part of your sample (the event handlers) but I assume it's not inside the double loop that is creating the polylines, right? So this is what I came up with:
marker.on('dragstart', function (e) {
var markerLatLng = marker.getLatLng();
this.polylineLatLngs = [];
for (var i = 0; i < $scope.polycoords.length; i++) {
var polyline = $scope.polycoords[i];
var latLngs = polyline.getLatLngs()
for (var j = 0; j < latLngs.length; j++) {
if (markerLatLng.equals(latLngs[j])) {
this.polylineLatLngs.push([i, j]);
}
}
}
});
marker.on('drag', function (e) {
for (var i = 0; i < this.polylineLatLngs.length; i++) {
var polyline = $scope.polycoords[this.polylineLatLngs[i][0]];
var latLngs = polyline.getLatLngs();
var markerLatLng = marker.getLatLng();
latLngs.splice(this.polylineLatLngs[i][1], 1, markerLatLng);
polyline.setLatLngs(latLngs);
}
});
I am getting this type of behavior. Please let me know how I can solve this .
Thank you for your time.
This is the polyline created by getting data from db or by making the connection between panorama.
This Image when I start dragging the marker 2 I got the result like this
This image when I dragged the marker 3.
This type of result I am getting using the source code you provided above.

Getting the bounds of loaded tile of leaflet

Using leaflet is there any way I can get the bounds (NorthEast, SouthWest) of a loaded tile? I want to request the server to load the markers only for a particular tile which is loaded, so that when user is panning/dragging the map he can easily see the new markers on new area.
What you really want to do is a subclass of L.GridLayer. This will allow fine control over loaded/unloaded tiles, and is the best way to use the private L.GridLayer._tileCoordsToBounds() method.
With some basic handling of loaded markers, it should look like:
L.GridLayer.MarkerLoader = L.GridLayer.extend({
onAdd: function(map){
// Add a LayerGroup to the map, to hold the markers
this._markerGroup = L.layerGroup().addTo(map);
L.GridLayer.prototype.onAdd.call(this, map);
// Create a tilekey index of markers
this._markerIndex = {};
},
onRemove: function(map){
this._markergroup.removeFrom(map);
L.GridLayer.prototype.onRemove.call(this, map);
};
createTile: function(coords, done) {
var tileBounds = this._tileCoordsToBounds(coords);
var tileKey = this._tileCoordsToKey(coords);
var url = ...; // Compute right url using tileBounds & coords.z
fetch(url).then(function(res){
if (!key in this._markerIndex) { this._markerIndex[key] = []; }
// unpack marker data from result, instantiate markers
// Loop as appropiate
this._markerGroup.addLayer(marker);
this._markerIndex[key] = marker;
done(); // Signal that the tile has been loaded successfully
});
},
_removeTile: function (key) {
for (var i in this._markerIndex[key]) {
this._markerGroup.remove(this._markerIndex[key][i]);
}
L.GridLayer.prototype._removeTile.call(this, key);
}
});
Please note that zooming might be a source of bugs and graphical glitches (markers being removed because a tile unloads, before the markers at the new zoom level are loaded). Beware of that.

Leaflet & Mapbox: OpenPopup not working

I've an issue with the leaflet openPopup method.
showMap = function(elements) {
var jsonp = 'http://a.tiles.mapbox.com/v3/blahblahblah.jsonp';
var m = new L.Map("my_map").setView(new L.LatLng(51.5, -0.09), 15);
var geojsonLayer = new L.GeoJSON();
var PlaceIcon = L.Icon.extend({
iconSize: new L.Point(25, 41),
shadowSize: new L.Point(40, 35),
popupAnchor: new L.Point(0, -30)
});
var icon = new PlaceIcon(__HOME__ + '/images/leaflet/marker.png');
var marker;
for (var i = 0; i < elements.length; i++) {
var address = $("<div/>").html(elements[i].address).text();
var latlng = new L.LatLng(elements[i].latitude, elements[i].longitude);
marker = new L.Marker(latlng, {icon: icon}).bindPopup(address);
if (i == 0) {
marker.openPopup();
}
m.addLayer(geojsonLayer).addLayer(marker);
}
// Get metadata about the map from MapBox
wax.tilejson(jsonp, function(tilejson) {
m.addLayer(new wax.leaf.connector(tilejson));
});
}
When I click on a marker I have the popup open. But I would like to have the first popup open when the map is loaded. (and open other popups on markers click)
AnNy ideas ?
Put openPopup call after you add the marker to the map and you should be fine.
I'm assuming that when you click on a marker you see the popup but you're not getting the popup of the first marker to show automatically when the map is loaded?
First, it doesn't look like you're actually using GeoJSON so a GeoJSON layer isn't necessary (you can just use a FeatureLayer) but that shouldn't cause any issues. Whatever layer group you use you should only be adding it to the map once and then adding all child layers to the LayerGroup. You're currently adding the geojsonLayer multiple times in your "for" loop which you don't want to do.
Second, you have to call marker.openPopup() after the marker is added to the map.
Try changing your code around to looks something like this:
var layerGroup = new L.FeatureGroup();
layerGroup.addTo( m );
for (var i = 0; i < elements.length; i++) {
var address = $("<div/>").html(elements[i].address).text();
var latlng = new L.LatLng(elements[i].latitude, elements[i].longitude);
marker = new L.Marker(latlng, {icon: icon}).bindPopup(address);
//You don't add the marker directly to the map. The layerGroup has already
//been added to the map so it will take care of adding the marker to the map
layerGroup.addLayer( marker );
if (i == 0) {
marker.openPopup();
}
}
I had this issue and fixed it with adding a timeout right after I added the marker on the map.
marker.addTo(this.map).bindPopup('Info');
setTimeout(() => {
marker.openPopup();
}, 500);
I don't know why but on some page, I need to apply timeout. In any case it's my workaround, hope this works for some of you too.
First add your map then put openPopup():
L.marker([lat, long]).bindPopup('Your message').addTo(map).openPopup();