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I'm running into issues as I am using Leaflet together with React, the issue being that Leaflet wants to control the DOM rendering as well, as far as I've researched.
Right now, the countries will correctly be colored with the specific color code corresponding with the backend information(range of 1-->100). However, it is updated every minute. Upon update, the country color will not change. It will however if you hover the mouse over a given country, which is a bit weird.
Here's my source code:
import React from 'react';
import L from 'leaflet';
import countries from './countries.js';
var Worldmap = React.createClass({
render: function() {
if(!this.props.data)
return <div> loading world map .. </div>;
let dataratio = this.props.data; // Props from main ponent
let size = Object.keys(dataratio).length; // Do we have data?
if(size > 1) { // If we do have data, ..
let dataratioToArr = Object.keys(dataratio).map(data => [ data, dataratio[data]]); // Conv. map to multidimensional array
let featuresArr = countries.features; // array of all countries in array features from countries.js
for(let i = 0; i < featuresArr.length; i++) // i = 178(no. of countries)
for(let j = 0; j < dataratioToArr.length; j++) // j = no. of countries we have with dataratio > 1 from backend
if(dataratioToArr[j][0] == featuresArr[i].id) // If ISO-3 pliant ID of country(f.e. "USA") matches, push a "data" property to countries.js
featuresArr[i].properties.data = dataratioToArr[j][1];
}
return(
<div id="leafletmap" style={{width: "100%", height: "80%", border: "2px solid black" }} />
)
},
ponentDidMount : function() {
let geolocation = [];
// Retrieve geoloc coordinates
navigator.geolocation.getCurrentPosition(function(position) {
let lat = position.coords.latitude;
let lon = position.coords.longitude;
if(lat != null && lon != null) // If we can get latitude and longitude, reset geolocation and push values.
geolocation.length = 0;
geolocation.push(lat, lon);
if(!lat || !lon) // If we can't get latitude or longitude, set a default value.
geolocation = [0,0];
let map = L.map('leafletmap').setView(geolocation, 3); // ([coordinates], zoomlevel)
let info = L.control();
info.onAdd = function (map) {
this._div = L.DomUtil.create('div', 'info');
this.update();
return this._div;
};
info.update = function (props) {
this._div.innerHTML = '<h4>Data ratio</h4>' + (props ?
'<b>' + props.name + '</b><br />' + props.data + ' ratio'
: 'Hover over a country');
};
info.addTo(map);
function getColor(d) {
return d > 90 ? '#4a1486' :
d > 75 ? '#6a51a3' :
d > 50 ? '#807dba' :
d > 25 ? '#9e9ac8' :
d > 15 ? '#bcbddc' :
d > 5 ? '#dadaeb' :
d > 1 ? '#f2f0f7' :
'#D3D3D3'; // Default color of data doesn't exist or is 0.
}
function style(feature) {
return {
weight: 2,
opacity: 1,
color: 'white',
fillOpacity: 1,
fillColor: getColor(feature.properties.data)
};
}
function highlightFeature(e) {
let layer = e.target;
layer.setStyle({
weight: 5,
color: '#666',
fillOpacity: 0.7
});
if (!L.Browser.ie && !L.Browser.opera && !L.Browser.edge) {
layer.bringToFront();
}
info.update(layer.feature.properties);
}
let geojson;
function resetHighlight(e) {
geojson.resetStyle(e.target);
info.update();
}
function zoomToFeature(e) {
map.fitBounds(e.target.getBounds());
}
function onEachFeature(feature, layer) {
layer.on({
mouseover: highlightFeature,
mouseout: resetHighlight,
click: zoomToFeature
});
}
geojson = L.geoJson(countries, { // from import
style: style,
onEachFeature: onEachFeature
}).addTo(map);
let legend = L.control({position: 'bottomright'});
legend.onAdd = function (map) {
let div = L.DomUtil.create('div', 'info legend'),
grades = [1, 5, 15, 25, 50, 75, 90],
labels = [],
from, to;
for (let i = 0; i < grades.length; i++) {
from = grades[i];
to = grades[i + 1];
labels.push(
'<i style="background:' + getColor(from + 1) + '"></i> ' +
from + (to ? '–' + to : '+'));
}
div.innerHTML = labels.join('<br>');
return div;
};
legend.addTo(map);
});
}
});
export default Worldmap
How do I force leaflet to redraw or refresh the map upon a new this.props.data being received?
I tried using ponentDidUpdate where I basically would do map.remove(), but then I run into scoping issues between the different ponents.. It's all loaded in ponentDidMount and if you call the leaflet map again it will say it's already initialized.
I'm running into issues as I am using Leaflet together with React, the issue being that Leaflet wants to control the DOM rendering as well, as far as I've researched.
Right now, the countries will correctly be colored with the specific color code corresponding with the backend information(range of 1-->100). However, it is updated every minute. Upon update, the country color will not change. It will however if you hover the mouse over a given country, which is a bit weird.
Here's my source code:
import React from 'react';
import L from 'leaflet';
import countries from './countries.js';
var Worldmap = React.createClass({
render: function() {
if(!this.props.data)
return <div> loading world map .. </div>;
let dataratio = this.props.data; // Props from main ponent
let size = Object.keys(dataratio).length; // Do we have data?
if(size > 1) { // If we do have data, ..
let dataratioToArr = Object.keys(dataratio).map(data => [ data, dataratio[data]]); // Conv. map to multidimensional array
let featuresArr = countries.features; // array of all countries in array features from countries.js
for(let i = 0; i < featuresArr.length; i++) // i = 178(no. of countries)
for(let j = 0; j < dataratioToArr.length; j++) // j = no. of countries we have with dataratio > 1 from backend
if(dataratioToArr[j][0] == featuresArr[i].id) // If ISO-3 pliant ID of country(f.e. "USA") matches, push a "data" property to countries.js
featuresArr[i].properties.data = dataratioToArr[j][1];
}
return(
<div id="leafletmap" style={{width: "100%", height: "80%", border: "2px solid black" }} />
)
},
ponentDidMount : function() {
let geolocation = [];
// Retrieve geoloc coordinates
navigator.geolocation.getCurrentPosition(function(position) {
let lat = position.coords.latitude;
let lon = position.coords.longitude;
if(lat != null && lon != null) // If we can get latitude and longitude, reset geolocation and push values.
geolocation.length = 0;
geolocation.push(lat, lon);
if(!lat || !lon) // If we can't get latitude or longitude, set a default value.
geolocation = [0,0];
let map = L.map('leafletmap').setView(geolocation, 3); // ([coordinates], zoomlevel)
let info = L.control();
info.onAdd = function (map) {
this._div = L.DomUtil.create('div', 'info');
this.update();
return this._div;
};
info.update = function (props) {
this._div.innerHTML = '<h4>Data ratio</h4>' + (props ?
'<b>' + props.name + '</b><br />' + props.data + ' ratio'
: 'Hover over a country');
};
info.addTo(map);
function getColor(d) {
return d > 90 ? '#4a1486' :
d > 75 ? '#6a51a3' :
d > 50 ? '#807dba' :
d > 25 ? '#9e9ac8' :
d > 15 ? '#bcbddc' :
d > 5 ? '#dadaeb' :
d > 1 ? '#f2f0f7' :
'#D3D3D3'; // Default color of data doesn't exist or is 0.
}
function style(feature) {
return {
weight: 2,
opacity: 1,
color: 'white',
fillOpacity: 1,
fillColor: getColor(feature.properties.data)
};
}
function highlightFeature(e) {
let layer = e.target;
layer.setStyle({
weight: 5,
color: '#666',
fillOpacity: 0.7
});
if (!L.Browser.ie && !L.Browser.opera && !L.Browser.edge) {
layer.bringToFront();
}
info.update(layer.feature.properties);
}
let geojson;
function resetHighlight(e) {
geojson.resetStyle(e.target);
info.update();
}
function zoomToFeature(e) {
map.fitBounds(e.target.getBounds());
}
function onEachFeature(feature, layer) {
layer.on({
mouseover: highlightFeature,
mouseout: resetHighlight,
click: zoomToFeature
});
}
geojson = L.geoJson(countries, { // from import
style: style,
onEachFeature: onEachFeature
}).addTo(map);
let legend = L.control({position: 'bottomright'});
legend.onAdd = function (map) {
let div = L.DomUtil.create('div', 'info legend'),
grades = [1, 5, 15, 25, 50, 75, 90],
labels = [],
from, to;
for (let i = 0; i < grades.length; i++) {
from = grades[i];
to = grades[i + 1];
labels.push(
'<i style="background:' + getColor(from + 1) + '"></i> ' +
from + (to ? '–' + to : '+'));
}
div.innerHTML = labels.join('<br>');
return div;
};
legend.addTo(map);
});
}
});
export default Worldmap
How do I force leaflet to redraw or refresh the map upon a new this.props.data being received?
I tried using ponentDidUpdate where I basically would do map.remove(), but then I run into scoping issues between the different ponents.. It's all loaded in ponentDidMount and if you call the leaflet map again it will say it's already initialized.
- 1 try to use React-Leaflet that will make the management of react life cycles and the map easier github./PaulLeCam/react-leaflet But as a possible solution direction in your case you should clearLayers on each new data update in ponentWillReceiveProps(nextProps) { if (nextProps.data !== this.props.data) { youMapRef.clearLayers(); } } – Alex Parij Commented Mar 21, 2017 at 13:25
1 Answer
Reset to default 3To extend my ment. You need to clear the layer and and re-add data to your map. It's possible that in your case you will need to change how you access the map and geojson processing but I'm giving you the general solution here.
ponentDidMount(){
var map = this.map = L.map('leafletmap');
}
ponentWillReceiveProps(nextProps) {
if (nextProps.data !== this.props.data) {
this.map.clearLayers();
}
}
ponentDidUpdate(prevProps,prevState) {
if (prevProps.data !== this.props.data) {
this.map.addData(geojsonData);
}
}
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