gis-api
Version:
GIS API for DHIS 2 based on Leaflet
89 lines (72 loc) • 2.68 kB
JavaScript
// Support both client and server clustering
// Currently not in use
import L from 'leaflet';
import clientCluster from './ClientCluster';
import serverCluster from './ServerCluster';
export const Cluster = L.Layer.extend({
options: {
clientClusterLimit: 2000,
fitBounds: true,
color: '#333',
opacity: 1,
},
initialize(options) {
L.setOptions(this, options);
this.initCluster();
},
onAdd(map) {
if (this._clusterLayer) {
map.addLayer(this._clusterLayer);
}
},
onRemove(map) {
if (this._clusterLayer && map.hasLayer(this._clusterLayer)) {
map.removeLayer(this._clusterLayer);
}
},
initCluster() {
const query = L.Util.template(this.options.query, this.options);
fetch(this.options.api + encodeURIComponent(query))
.then(response => response.json())
.then(data => this.onInitLoad(data.rows[0]))
.catch(ex => {
window.console.log('parsing failed', ex); // TODO
});
},
onInitLoad(data) {
const options = this.options;
if (options.fitBounds) {
this._map.fitBounds(this._boxToBounds(data.extent));
}
if (options.clustering !== 'server' && data.count <= options.clientClusterLimit) {
this.initClientCluster();
} else {
this.initServerCluster(data.count);
}
},
initClientCluster() {
this._clusterLayer = clientCluster(L.extend(this.options, {
query: 'SELECT uid, ST_AsGeoJSON(the_geom) AS geom FROM {table}',
})).addTo(this._map);
},
initServerCluster(count) {
this._clusterLayer = serverCluster(L.extend(this.options, {
query: 'SELECT COUNT(uid) AS count, CASE WHEN COUNT(uid) <= 20 THEN array_agg(uid) END AS ids, ST_AsGeoJSON(ST_Centroid(ST_Collect(the_geom)),5) AS center, ST_Extent(the_geom) AS bounds FROM (SELECT cartodb_id AS uid, the_geom FROM {table}) sq WHERE the_geom && ST_MakeEnvelope({bounds}, 4326) GROUP BY ST_SnapToGrid(ST_Transform(the_geom, 3785), {size})',
domain: [1, count],
})).addTo(this._map);
},
setOpacity(opacity) {
this.options.opacity = opacity;
if (this._clusterLayer) {
this._clusterLayer.setOpacity(opacity);
}
},
// Converts a PostGIS box2d to Leaflet bounds
_boxToBounds(box) {
const coords = box.match(/[0-9\.\-]+/g);
return [[coords[1], coords[0]], [coords[3], coords[2]]];
},
});
export default function cluster(options) {
return new Cluster(options);
}