mapcomplete/Logic/FeatureSource/Sources/GeoJsonSource.ts

141 lines
5.1 KiB
TypeScript

/**
* Fetches a geojson file somewhere and passes it along
*/
import {UIEventSource} from "../../UIEventSource";
import FilteredLayer from "../../../Models/FilteredLayer";
import {Utils} from "../../../Utils";
import {FeatureSourceForLayer, Tiled} from "../FeatureSource";
import {Tiles} from "../../../Models/TileRange";
import {BBox} from "../../BBox";
import {GeoOperations} from "../../GeoOperations";
export default class GeoJsonSource implements FeatureSourceForLayer, Tiled {
public readonly features: UIEventSource<{ feature: any; freshness: Date }[]>;
public readonly name;
public readonly isOsmCache: boolean
public readonly layer: FilteredLayer;
public readonly tileIndex
public readonly bbox;
private readonly seenids: Set<string>;
private readonly idKey ?: string;
public constructor(flayer: FilteredLayer,
zxy?: [number, number, number] | BBox,
options?: {
featureIdBlacklist?: Set<string>
}) {
if (flayer.layerDef.source.geojsonZoomLevel !== undefined && zxy === undefined) {
throw "Dynamic layers are not supported. Use 'DynamicGeoJsonTileSource instead"
}
this.layer = flayer;
this.idKey = flayer.layerDef.source.idKey
this.seenids = options?.featureIdBlacklist ?? new Set<string>()
let url = flayer.layerDef.source.geojsonSource.replace("{layer}", flayer.layerDef.id);
if (zxy !== undefined) {
let tile_bbox: BBox;
if (zxy instanceof BBox) {
tile_bbox = zxy;
} else {
const [z, x, y] = zxy;
tile_bbox = BBox.fromTile(z, x, y);
this.tileIndex = Tiles.tile_index(z, x, y)
this.bbox = BBox.fromTile(z, x, y)
url = url
.replace('{z}', "" + z)
.replace('{x}', "" + x)
.replace('{y}', "" + y)
}
let bounds: { minLat: number, maxLat: number, minLon: number, maxLon: number } = tile_bbox
if (this.layer.layerDef.source.mercatorCrs) {
bounds = tile_bbox.toMercator()
}
url = url
.replace('{y_min}', "" + bounds.minLat)
.replace('{y_max}', "" + bounds.maxLat)
.replace('{x_min}', "" + bounds.minLon)
.replace('{x_max}', "" + bounds.maxLon)
} else {
this.tileIndex = Tiles.tile_index(0, 0, 0)
this.bbox = BBox.global;
}
this.name = "GeoJsonSource of " + url;
this.isOsmCache = flayer.layerDef.source.isOsmCacheLayer;
this.features = new UIEventSource<{ feature: any; freshness: Date }[]>([])
this.LoadJSONFrom(url)
}
private LoadJSONFrom(url: string) {
const eventSource = this.features;
const self = this;
Utils.downloadJson(url)
.then(json => {
if (json.features === undefined || json.features === null) {
return;
}
if (self.layer.layerDef.source.mercatorCrs) {
json = GeoOperations.GeoJsonToWGS84(json)
}
const time = new Date();
const newFeatures: { feature: any, freshness: Date } [] = []
let i = 0;
let skipped = 0;
for (const feature of json.features) {
const props = feature.properties
for (const key in props) {
if(props[key] === null){
delete props[key]
}
if (typeof props[key] !== "string") {
// Make sure all the values are string, it crashes stuff otherwise
props[key] = JSON.stringify(props[key])
}
}
if(self.idKey !== undefined){
props.id = props[self.idKey]
}
if (props.id === undefined) {
props.id = url + "/" + i;
feature.id = url + "/" + i;
i++;
}
if (self.seenids.has(props.id)) {
skipped++;
continue;
}
self.seenids.add(props.id)
let freshness: Date = time;
if (feature.properties["_last_edit:timestamp"] !== undefined) {
freshness = new Date(props["_last_edit:timestamp"])
}
newFeatures.push({feature: feature, freshness: freshness})
}
if (newFeatures.length == 0) {
return;
}
eventSource.setData(eventSource.data.concat(newFeatures))
}).catch(msg => console.debug("Could not load geojson layer", url, "due to", msg))
}
}