src/layers/LayerBaseVectorGeoJson.js
/**
* Created by gavorhes on 11/2/2015.
*/
import $ from '../jquery/jquery';
import LayerBaseVector from './LayerBaseVector';
import provide from '../util/provide';
import ol from '../ol/ol';
let nm = provide('layers');
/**
* The Vector GeoJson Layer
* @augments LayerBaseVector
*/
class LayerBaseVectorGeoJson extends LayerBaseVector {
/**
* @param {string|undefined|null} url - resource url, set to '' to make blank layer
* @param {object} options - config
* @param {string} [options.id] - layer id
* @param {string} [options.name=Unnamed Layer] - layer name
* @param {number} [options.opacity=1] - opacity
* @param {boolean} [options.visible=true] - default visible
* @param {number} [options.minZoom=undefined] - min zoom level, 0 - 28
* @param {number} [options.maxZoom=undefined] - max zoom level, 0 - 28
* @param {object} [options.params={}] the get parameters to include to retrieve the layer
* @param {number} [options.zIndex=0] the z index for the layer
* @param {function} [options.loadCallback] function to call on load, context this is the layer object
* @param {boolean} [options.legendCollapse=false] if the legend item should be initially collapsed
* @param {boolean} [options.legendCheckbox=true] if the legend item should have a checkbox for visibility
* @param {boolean} [options.legendContent] additional content to add to the legend
*
* @param {boolean} [options.autoLoad=false] if the layer should auto load if not visible
* @param {object} [options.style=undefined] the layer style, use openlayers default style if not defined
* @param {boolean} [options.onDemand=false] if the layer should be loaded by extent on map move
* @param {number} [options.onDemandDelay=300] delay before the map move callback should be called
*
* @param {object} [options.transform={}] SR transform, set as false for no transform
* @param {string} options.transform.dataProjection=EPSG:4326 the data CRS
* @param {string} options.transform.featureProjection=EPSG:3857 the feature/map CRS
* @param {mapMoveMakeGetParams} [options.mapMoveMakeGetParams=function(lyr, extent, zoomLevel){}] function to create additional map move params
* @param {MapMoveCls} [options.mapMoveObj=mapMove] alternate map move object for use with multi map pages
*/
constructor(url, options) {
url = typeof url == 'string' ? url : '';
super(url, options);
this._geoJsonFormat = new ol.format.GeoJSON();
this._transform = options.transform || {};
this._transform.dataProjection = this._transform.dataProjection || "EPSG:4326";
this._transform.featureProjection = this._transform.featureProjection || "EPSG:3857";
if (this.autoLoad || this.visible) {
this._load();
}
}
/**
* add feature collection
* @param {object} featureCollection - as geojson object
*/
addFeatures(featureCollection) {
if (this._transform.dataProjection == 'EPSG:3857' && this._transform.featureProjection == 'EPSG:3857') {
this._source.addFeatures(this._geoJsonFormat.readFeatures(featureCollection));
} else {
this._source.addFeatures(this._geoJsonFormat.readFeatures(featureCollection, this._transform));
}
}
/**
* trigger load features
* @protected
* @returns {boolean} if already loaded
*/
_load() {
if (super._load()) {
return true;
}
$.get(this._url,
this._params,
(d) => {
this.addFeatures(d);
this.loadCallback(this);
}, 'json').fail(
function () {
this._loaded = false;
}
);
return false;
}
/**
* callback function on map move
* @param {object} d the json response
* @override
*/
mapMoveCallback(d) {
super.mapMoveCallback(d);
this._source.addFeatures(this._geoJsonFormat.readFeatures(d, this._transform));
}
}
nm.LayerBaseVectorGeoJson = LayerBaseVectorGeoJson;
export default LayerBaseVectorGeoJson;