can't implement L.mapbox.simplestyle with geoJson - leaflet

I'm trying to implement simplestyle's options for marker size and color , but can't get them to render. In this simple test case, I'm trying to follow Mapbox's own example quite closely:
var myData = [
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [4.509373,51.932994]
},
"properties": {
"marker-size": "large",
"marker-color": "#ffcc00"
}
}
];
var map = L.mapbox.map('map', 'examples.map-20v6611k')
.setView([51.932994,4.509373], 8);
L.geoJson(myData, { style: L.mapbox.simplestyle.style }).addTo(map);
fiddle
But the marker renders in default style. What am I missing?

OK, I've got it working using this extended function from this page of Mapbox's documentation:
L.geoJson(myData, {
pointToLayer: L.mapbox.marker.style,
style: function(feature) { return feature.properties; }
}).addTo(map);
The other Mapbox example didn't make it look like the pointToLayer argument was required, but whatever works:
fiddle

Another alternative would be to create a featureLayer based on your myData:
var featureLayer = L.mapbox.featureLayer(myData).addTo(map);
Your data will have to be an object, however, and not an array:
var myData = {
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [4.509373,51.932994]
},
"properties": {
"marker-size": "large",
"marker-color": "#ffcc00"
}
};

Related

Heatmap from geojson points in leaflet

I am attempting to create a simple heatmap from a feature collection of points using leaflet's heatmap plugin. After successfully getting the json data from an ajax call, I create an empty coords array and push coordinates from each feature.
However, this method does not work and neither does the geojson2heat function. There are no errors in the console. What am I doing wrong and does anyone know of a workaround?
var map = L.map('map').setView([50.0647, 19.9450], 12);
var tiles = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
attribution: '© OpenStreetMap contributors',
}).addTo(map);
var geojsonLayer = new L.GeoJSON.AJAX("newmap.geojson");
coords = [];
function onEachFeature(feature, layer) {
coords.push(feature.geometry.coordinates);
};
L.GeoJSON(geojsonLayer, {
onEachFeature: onEachFeature
})
var heat = L.heatLayer(coords).addTo(map);
The structure of the geojson is standard:
{
"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
"features": [
{ "type": "Feature", "properties": { "st_x": 19.952030181884801, "st_y": 50.055513141929701 }, "geometry": { "type": "Point", "coordinates": [ 19.952030181884801, 50.055513141929701 ] } },
{ "type": "Feature", "properties": { "st_x": 18.672015, "st_y": 50.287181666666697 }, "geometry": { "type": "Point", "coordinates": [ 18.672015, 50.287181666666697 ] } },
I am mostly doing the same as you but with Mapbox, which is based on Leaflet.
The problem I had is that the latitude and longitude coordinates of the GeoJSON were reversed. There were no errors on console either- points were just not showing on map. So, you need:
"coordinates": [ longitude, latitude ]
Hope that's the issue.

How to convert geojson to polygon in Leaflet?

I have this json data:
var states = [{
"type": "Feature",
"properties": {"party": "Republican"},
"geometry": {
"type": "Polygon",
"coordinates": [[
[-104.05, 48.99],
[-97.22, 48.98],
[-96.58, 45.94],
[-104.03, 45.94],
[-104.05, 48.99]
]]
}
}
}];
It'is easy to visualize this on leaflet map by doing this:
L.geoJSON(states, {
style: function(feature) {
switch (feature.properties.party) {
case 'Republican': return {color: "#ff0000"};
}
}
}).addTo(map);
But i need the "type" of states is "polygon" not "geojson", so the result will be like this:
var states_polygon = L.polygon([[
[48.99,-104.05],
[48.98,-97.22],
[45.94,-96.58],
[45.94,-104.03],
[48.99,-104.05]
]]).addTo(map);
I knew that both variable will be give the same visual on leaflet map but all i need is the object type of that variable as polygon.. How can i do this?

Access geojson property of a layer in a featuregroup in Mapbox

I have a GEOJSON which I added to the featuregroup in my Mapbox map like this:
var featureCollection = {
"type": "FeatureCollection",
"features": [{
"type": "Feature",
"properties": {
"id": 1
},
"geometry": {
"type": "Point",
"coordinates": [0, 0]
}
},{
"type": "Feature",
"properties": {
"id": 2
},
"geometry": {
"type": "Point",
"coordinates": [30, 30]
}
},{
"type": "Feature",
"properties": {
"id": 3
},
"geometry": {
"type": "Point",
"coordinates": [-30, -30]
}
}]
};
var geojson = L.geoJson(featureCollection);
var featureGroup = L.featureGroup().addTo(map);
featureGroup.addLayer(geojson);
Now, I wish to access the id property of each layer while looping through the featuregroup, so that I can pass it as an argument to another function. In the case of a featurelayer, I can easily access it using something like this:
var featureLayer = L.mapbox.featureLayer(featureCollection).addTo(map);
featureLayer.eachLayer(function (layer) {
layer.on('click', function (e) {
console.log('Clicked feature ID: ' + e.target.feature.properties.id);
});
});
But I want to be able to access it while looping inside a featuregroup, and also I want to be able to do it without a 'click' or any such event. For example, ideally I would use something like this:
featureGroup.eachLayer(function (layer) {
var id = layer.feature.properties.id;
testfunction(id);
});
I haven't been able to figure out how to do that. I've tried searching online, but because I'm new to this, I probably haven't been using the right keywords in my search.
geojson is nested within featureGroup, so when your eachLayer function runs, it is not operating on the individual features within geojson, but instead on geojson itself. To extract each feature's id property, you will need to go one level deeper and iterate over the features within geojson.
Fortunately, the L.GeoJson class also supports the eachLayer method (because it is an extension of L.FeatureGroup, which is itself an extension of L.LayerGroup). To print the id of each feature, you could just use the eachLayer method directly on geojson:
geojson.eachLayer(function (layer) {
var id = layer.feature.properties.id;
testfunction(id);
});
Or, if you have a bunch of L.GeoJson objects nested within featureGroup, you can use:
featureGroup.eachLayer(function (layer) {
layer.eachLayer(function (layer) {
var id = layer.feature.properties.id;
testfunction(id);
});
});

L.circleMarker on MapBox with options does not work

I am trying to add a circle marker to my MapBox but passed options doesn't do what its supposed to do. I am using following code
L.mapbox.featureLayer(
{ "geometry": {"type": "Point", "coordinates": [lng , lat]}, "type": "Feature", "properties": {} },
{ pointToLayer: function(feature, latlon) {
var marker = L.circleMarker(latlon, {
radius: 2,
color: "#ff0000"
});
return marker;
} }
).addTo(map);
the radius is set but the color is set to default.
This was a bug in Mapbox.js 2.1.8: if you update to 2.1.9, the issue should be resolved.

addingand using marker variable with geoJsonData and markercluster with leaflet.js

I've been searching for hours and hours now, and i'm still stuck. I have a feeling it is something easy/stupid i'm missing.
I am using the example of markercluster from GitHub. I have 2 different markers (simply 2 different colors) that i would like to show which i would defined in the json format.
I have followed guide from leaflet site to define different markers.
I added my variable to the json part, but i can not figure out how to make the map load the different markers. It's either giving me no map or error; or it still uses the default blue marker.
here is my code:
<script type="text/javascript">
var geoJsonData = {
"type": "FeatureCollection",
"features": [
{ "type": "Feature", "id":"1", "properties": { "address": "2","marker": "cmIcon"}, "geometry": { "type": "Point", "coordinates": [175.2209316333,-37.8210922667 ] } },
{ "type": "Feature", "id":"2", "properties": { "address": "151","marker": "otherIcon" }, "geometry": { "type": "Point", "coordinates": [175.2238417833,-37.80975435 ] } },
{ "type": "Feature", "id":"3", "properties": { "address": "21","marker": "cmIcon" }, "geometry": { "type": "Point", "coordinates": [175.2169955667,-37.818193 ] } },
{ "type": "Feature", "id":"4", "properties": { "address": "14","marker": "otherIcon" }, "geometry": { "type": "Point", "coordinates": [175.2240856667,-37.8216963 ] } },
{ "type": "Feature", "id":"5", "properties": { "address": "38B","marker": "cmIcon" }, "geometry": { "type": "Point", "coordinates": [175.2196982333,-37.8188702167 ] } },
{ "type": "Feature", "id":"6", "properties": { "address": "38","marker": "otherIcon" }, "geometry": { "type": "Point", "coordinates": [175.2209942 ,-37.8192782833 ] } }
]
};
var cloudmade = L.tileLayer('http://{s}.tile.cloudmade.com/{key}/997/256/{z}/{x}/{y}.png', {
maxZoom: 18,
attribution: 'Map data © 2011 OpenStreetMap contributors, Imagery © 2011 CloudMade',
key: 'BC9A493B41014CAABB98F0471D759707'
});
var LeafIcon = L.Icon.extend({
options: {
shadowUrl: 'marker/marker-shadow.png',
iconSize: [32, 32],
shadowSize: [36, 20],
iconAnchor: [22, 94],
shadowAnchor: [4, 62],
popupAnchor: [-3, -76]
}
});
var cmIcon = new LeafIcon({iconUrl: 'marker/marker-cm.png'}),
otherIcon = new LeafIcon({iconUrl: 'marker/marker-others.png'});
var map = L.map('map')
.addLayer(cloudmade);
var markers = new L.MarkerClusterGroup();
var geoJsonLayer = L.geoJson(geoJsonData, {
onEachFeature: function (feature, layer) {
layer.bindPopup(feature.properties.address);
}
});
markers.addLayer(geoJsonLayer);
map.addLayer(markers);
map.fitBounds(markers.getBounds());
function onLocationFound(e) {
var radius = e.accuracy / 2;
L.marker(e.latlng).addTo(map)
.bindPopup("Vous etes ici").openPopup();
L.circle(e.latlng, radius).addTo(map);
}
function onLocationError(e) {
alert(e.message);
}
map.on('locationfound', onLocationFound);
map.on('locationerror', onLocationError);
map.locate({setView: true, maxZoom: 16});
</script>
I suspect that i need to tell leaflet to get the marker variable, probably in
var geoJsonLayer = L.geoJson(geoJsonData, {
onEachFeature: function (feature, layer) {
layer.bindPopup(feature.properties.address);
}
});
but i cannot make it work.
i even tried as suggested some where else:
var geoJsonLayer = L.geoJson(geoJsonData, {
onEachFeature: function (feature, layer) {
layer.bindPopup(feature.properties.address),
layer.setIcon(feature.properties.marker);
}
});
i'm still getting an error: Uncaught TypeError: Object cmIcon has no method 'createIcon'
does anybody have an idea on how to do that?
Any help would be greatly appreciated.
Thank you in advance.
You need to tell the MarkerClusterGroup how to create the icon. The marker cluster docs show an example with a DivIcon like this:
var markers = new L.MarkerClusterGroup({
iconCreateFunction: function(cluster) {
return new L.DivIcon({ html: '<b>' + cluster.getChildCount() + '</b>' });
}
});
You can use your custom icon instead like this:
var markers = new L.MarkerClusterGroup({
iconCreateFunction: function(cluster) {
// decide which icon you want to use
return (cluster.getChildCount() > 10) ? cmIcon : otherIcon;
}
});