/* global L */
(function() {
L.GeoJSONLayer = L.GeoJSON.extend({
includes: L.Evented.prototype,
url: null,
map: null,
//
// Leaflet layer methods
//
initialize(url, options) {
this.url = url;
L.GeoJSON.prototype.initialize.call(this, [], options);
},
onAdd(map) {
L.GeoJSON.prototype.onAdd.call(this, map);
this.map = map;
map.on('moveend zoomend refresh', this._reloadMap, this);
this._reloadMap();
},
onRemove(map) {
map.off('moveend zoomend refresh', this._reloadMap, this);
this.map = null;
L.GeoJSON.prototype.onRemove.call(this, map);
},
//
// Custom methods
//
_reloadMap: function() {
if (this.map) {
var url = this._expandUrl(this.url);
this._ajaxRequest('GET', url, false, this._updateLayers.bind(this));
}
},
_expandUrl: function(template) {
var bbox = this.map.getBounds();
var southWest = bbox.getSouthWest();
var northEast = bbox.getNorthEast();
var bboxStr = bbox.toBBoxString();
var coords = {
lat1: southWest.lat,
lon1: southWest.lng,
lat2: northEast.lat,
lon2: northEast.lng,
bbox: bboxStr
};
return L.Util.template(template, coords);
},
_ajaxRequest: function(method, url, data, callback) {
var request = new XMLHttpRequest();
request.open(method, url, true);
request.onreadystatechange = function() {
if (request.readyState === 4 && request.status === 200) {
callback(JSON.parse(request.responseText));
}
};
if (data) {
request.setRequestHeader('Content-type', 'application/json');
request.send(JSON.stringify(data));
} else {
request.send();
}
return request;
},
_updateLayers: function(geoData) {
this.clearLayers();
this.addData(geoData);
}
});
L.geoJSONLayer = function (url, options) {
return new L.GeoJSONLayer(url, options);
};
})();
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