I place polygons in front of a map. Some smaller polygons are placed in front of a bigger polygon. I get the data from geojson file. I want to show the name-poperty as a popup. I use:
function onEachFeature(feature, layer) {
layer.bindPopup(layer.feature.properties.name);
};
Unfortunately only the name-property of the bigger ploygon is shown. How can i correct this? I tried an additionl geojson-property with:
function onEachFeature(feature, layer) {
if ((feature.properties.popupContent != "0"))
{layer.bindPopup(layer.feature.properties.name);
};
};
But this does not work too.
thanks, wonk
Leaflet provides a couple of functions to help access smaller markers that may be trapped under larger markers, those being the .bringToFront() and .bringToBack() methods provided by L.Path, L.featureGroup, and L.GridLayer and inherited by any descendants of those. I've set up a live, rudimentary example of using these to access trapped markers on StackBlitz.
Thank you for the example, I understand. I tried:
function onEachFeature(feature, layer) {
if ((feature.properties.popupContent != "0"))
{layer.bindPopup(layer.feature.properties.name);
layer.bringToFront();
};
}
But this only shows the first polygon (there are a lot of them). Maybe, I misunderstood the geojson-data. I thought, there is one layer for every polygon. But it seems, that all polygons of geojson-data-file are in ONE layer. In this case your proposal won't work, I think. I will have to find another solution. The data come from:
function show_geojson (overlay) {
$.ajax({url:overlay}).done(function(data) {
var data = JSON.parse(data);
L.geoJson(data,
{pointToLayer: MarkerStyle,
style: style,
onEachFeature: onEachFeature
});
geoJsonLayer = L.geoJson(data); //neu
});
}
Thank you!
Related
I'm a complete beginner when it comes to leaflet but i'm slowly but surely learning the ropes after an introduction course. I've read over the Leaflet documentation but i'm still having trouble combining a permanent toolTip (label) with a bindPopup on click.
I can find success in doing one OR the other but not both. See below for my current code that labels each feature of my geoJSON multipolygon. I would now also like to display feature attribute information from the geoJSON in a popup when that feature polygon is clicked.
var lyrNeighbourhoods= new L.GeoJSON.AJAX("data/Neigh_Demo1.geojson",
{style: {weight:1, fillOpacity:0.1},
onEachFeature: function (feature, layer) {
layer.bindTooltip(feature.properties.Neigh_Name, {direction:"center",permanent:true,
className: 'labelstyle'});
}
}).addTo(mymap);
I've been racking my brain over this for too long. Any help is appreciated.
In your onEachFeature option function, there is nothing stopping you from also attaching a popup to your Layer:
function (feature, layer) {
layer.bindTooltip(feature.properties.Neigh_Name, {
direction: "center",
permanent: true,
className: 'labelstyle'
});
layer.bindPopup("My popup content");
}
I am exporting Google Directions routes as KML and displaying them on a Mapbox map by reading them with Omnivore and adding them to the map,
The Google KML stores each route as two Places (the start and end points) and one LineString (the route). In Mapbox I would like to show only the routes, that is to filter out the markers somehow. I'm displaying markers out of my own database and the Google markers clutter it up.
Here is my code. I change the styling of the LineStrings just to show that I can, but do not know what magic call(s) to make to not display the Points.
Thanks.
runLayer = omnivore.kml('data/xxxx.kml')
.on('ready', function() {
var llBnds = runLayer.getBounds();
map.fitBounds(llBnds);
this.eachLayer(function (layer) {
if (layer.feature.geometry.type == 'LineString') {
layer.setStyle({
color: '#4E3508',
weight: 4
});
}
if (layer.feature.geometry.type == 'Point') {
//
// Do something useful here to not display these items!!
//
}
});
})
.addTo(map);
Welcome to SO!
Many possible solutions:
Most straight forward from the code you provided, just use the removeLayer method on your runLayer Layer Group when you get a 'Point' feature.
Cleaner solution would be to filter out those features before they are even converted into Leaflet layers, through a custom GeoJSON Layer Group passed as 3rd argument of omnivore.kml, with a specified filter option:
var customLayer = L.geoJSON(null, {
filter: function(geoJsonFeature) {
// my custom filter function: do not display Point type features.
return geoJsonFeature.geometry.type !== 'Point';
}
}).addTo(map);
var runLayer = omnivore.kml('data/xxxx.kml', null, customLayer);
You can also use the style and/or onEachFeature options on customLayer to directly apply your desired style on your LineString.
I would like to have certain layers to be always on top of others, no matter in which order they are added to the map.
I am aware of bringToFront(), but it does not meet my requirements. I would like to set the zIndex dynamically based on properties.
Leaflet has the method setZIndex(), but this apparently does not work for geoJson layers:
https://jsfiddle.net/jw2srhwn/
Any ideas?
Cannot be done for vector geometries.
zIndex is a property of HTMLElements, and vector geometries (lines and polygons) are rendered as SVG elements, or programatically as <canvas> draw calls. Those two methods have no concept of zIndex, so the only thing that works is pushing elements to the top (or bottom) of the SVG group or <canvas> draw sequence.
Also, remind that L.GeoJSON is just a specific type of L.LayerGroup, in your case containing instances of L.Polygon. Furthermore, if you read Leaflet's documentation about the setZIndex() method on L.LayerGroup:
Calls setZIndex on every layer contained in this group, passing the z-index.
So, do L.Polygons have a setZIndex() method? No. So calling that in their containing group does nothing. It will have an effect on any L.GridLayers contained in that group, though.
Coming back to your problem:
I would like to have certain layers to be always on top of others, no matter in which order they are added to the map.
Looks like the thing you're looking for is map panes. Do read the map panes tutorial.
This is one of the reason for the implementation of user defined "panes" in Leaflet 1.0 (compared to versions 0.x).
Create panes: var myPane = map.createPane("myPaneName")
If necessary, set the class / z-index of the pane element: myPane.style.zIndex = 450 (refer to z-index values of built-in panes)
When creating your layers, specify their target pane option: L.rectangle(corners, { pane: "myPaneName" })
When building through the L.geoJSON factory, you can loop through your features with the onEachFeature option to clone your layers with specified target pane.
Demo: https://jsfiddle.net/3v7hd2vx/90/
For peoples who are searching about Z-Index
All path layers (so all except for markers) have no z-index because svg layers have a fix order. The first element is painted first. So the last element is painted on top.
#IvanSanchez described good why zIndex not working.
You can control the order with layer.bringToBack() or layer.bringToFront().
With that code you have more options to control the order of the layers.
L.Path.include({
getZIndex: function() {
var node = this._path;
var index = 0;
while ( (node = node.previousElementSibling) ) {
index++;
}
return index;
},
setZIndex: function(idx) {
var obj1 = this._path;
var parent = obj1.parentNode;
if(parent.childNodes.length < idx){
idx = parent.childNodes.length-1;
}
var obj2 = parent.childNodes[idx];
if(obj2 === undefined || obj2 === null){
return;
}
var next2 = obj2.nextSibling;
if (next2 === obj1) {
parent.insertBefore(obj1, obj2);
} else {
parent.insertBefore(obj2, obj1);
if (next2) {
parent.insertBefore(obj1, next2);
} else {
parent.appendChild(obj1);
}
}
},
oneUp: function(){
this.setZIndex(this.getZIndex()+1)
},
oneDown: function(){
this.setZIndex(this.getZIndex()-1)
}
});
Then you can call
polygon.oneUp()
polygon.oneDown()
polygon.setZIndex(2)
polygon.getZIndex()
And now layergroup.setZIndex(2) are working
I'm trying to make a mapping visualization in realtime, where I keep getting new points via websockets. The initial plotting these markers on the map seems simple, but I'm not sure what's the right way of updating a layer on Mapbox.
As of now, whenever I get a new point, I remove the old layer, create a new one and then add it on the map. The problem with this approach is that it is slow and for high number of points (>5000) it starts lagging.
// remove layer
if (this.pointsLayer != null) {
map.removeLayer(this.pointsLayer);
}
// build geoJSON
var geoJSON = { "type": "FeatureCollection", "features": [] };
geoJSON["features"] = tweets.map(function(tweet) {
return this.getGeoPoint(tweet);
}.bind(this));
// add geoJSON to layer
this.pointsLayer = L.mapbox.featureLayer(geoJSON, {
pointToLayer: function(feature, latlon) {
return L.circleMarker(latlon, {
fillColor: '#AA5042',
fillOpacity: 0.7,
radius: 3,
stroke: false
});
}
}).addTo(map);
Is there a better way?
You can create an empty GeoJSON layer by passing it a false instead of real data:
//create empty layer
this.pointsLayer = L.mapbox.featureLayer(false, {
pointToLayer: function(feature, latlon) {
return L.circleMarker(latlon, {
fillColor: '#AA5042',
fillOpacity: 0.7,
radius: 3,
stroke: false
});
}
}).addTo(map);
then use .addData to update it as new tweets come in. Something like:
// build geoJSON
var geoJSON = { "type": "FeatureCollection", "features": [] };
geoJSON["features"] = /**whatever function you use to build a single tweet's geoJSON**/
// add geoJSON to layer
this.pointsLayer.addData(geoJSON);
For a single tweet, I guess you could just create a Feature instead of a FeatureCollection, though I don't know whether that extra layer of abstraction would make any difference in terms of performance.
EDIT: Here is an example fiddle showing the .addData method at work:
http://jsfiddle.net/nathansnider/4mwrwo0t/
It does slow down noticeably if you add 10,000 points, and for 15,000 points, it's really sluggish, but I suspect that has less to do with how the points are added that the demands of rendering so many circleMarkers.
If you aren't already, you may want to try using the new Leaflet 1.0 beta, which redraws vector layers faster and is generally much more responsive with large datasets. Compare this 15,000-point example using Leaflet 0.7.5 to the same code using Leaflet 1.0.0b2. Not everything is fixed (popups take a long time to open in both), but the difference in lag time when trying to drag the map is pretty dramatic.
There's no reason to go through the intermediate step of construction a GeoJSON object just so you can add it to the map. Depending on your exact needs, you can do something like this:
tweets.forEach(function(t) {
L.marker(this.getGeoPoint(t)).addTo(map);
}, this);
You should manage the tweets object so it only contains points that are not already visible on the map, though. Deleting all the old markers, just so you can add them again, is of course going to be very slow.
I would take a look at Leaflet Realtime:
Put realtime data on a Leaflet map: live tracking GPS units, sensor data or just about anything.
https://github.com/perliedman/leaflet-realtime
I load some lat / lon info, then use it to build a polyline.
I then want to add a marker at each of the polyline vertices that will show when the polyline is clicked.
The vertices should disappear if a different (or the same) polyline is clicked.
The code below creates the polyline and the vertex markers.
But the vertex markers do not ever disappear.
I've tried to do this several ways with the same result. I've tried storing the vertex markers in an array and adding them directly to the map, then map.removeLayer'ing them. That doesn't work either. Nor does it work if I use an L.featureGroup instead of a layerGroup.
Clearly I've missed the point somewhere as to how markers can be removed. Could someone point me at the error in my methodology?
// trackMarkersVisible is a global L.layerGroup
// success is a callback from an ajax that fetches trackData, an array f lat/lon pairs
success: function (trackData) {
// build an array of latLng's
points = buildTrackPointSet(trackData, marker.deviceID);
var newTrack = L.polyline(
points, {
color: colors[colorIndex],
weight: 6,
clickable: true
}
);
$(newTrack).on("click", function () {
trackMarkersVisible.clearLayers();
$.each(points, function(idx, val) {
var tm = new L.Marker(val);
trackMarkersVisible.addLayer(tm);
});
map.addLayer(trackMarkersVisible);
});
}
Without a JSFiddle or Plunker it's hard to say because i'm not sure what behaviour your getting but using the clearLayers() method of L.LayerGroup should remove all layers from that group. I would check in the onclick handler if the group already has layers: group.getLayers().length === 0 If the group is empty, add the markers, if the group has layers use clearLayers. Example in code:
polyline.on('click', function (e) {
if (group.getLayers().length === 0) {
e.target._latlngs.forEach(function (latlng) {
group.addLayer(L.marker(latlng));
});
} else {
group.clearLayers();
}
});
This works for me, see the example on Plunker: http://plnkr.co/edit/7IPHrO?p=preview
FYI: an instance of L.Polyline is always clickable by default so you can leave out the clickable: true