import FeatureSource from "./FeatureSource"; import {UIEventSource} from "../UIEventSource"; export default class FeatureSourceMerger implements FeatureSource { public features: UIEventSource<{ feature: any; freshness: Date }[]> = new UIEventSource<{feature: any; freshness: Date}[]>([]); private readonly _sources: FeatureSource[]; constructor(sources: FeatureSource[]) { this._sources = sources; const self = this; for (const source of sources) { source.features.addCallback(() => self.Update()); } } private Update() { let all = {}; // Mapping 'id' -> {feature, freshness} for (const source of this._sources) { for (const f of source.features.data) { const id = f.feature.properties.id+f.feature.geometry.type+f.feature._matching_layer_id; const oldV = all[id]; if(oldV === undefined){ all[id] = f; }else{ if(oldV.freshness < f.freshness){ all[id]=f; } } } } const newList = []; for (const id in all) { newList.push(all[id]); } this.features.setData(newList); } }