mapcomplete/Logic/FeatureSource/Sources/RememberingSource.ts
2021-11-07 16:34:51 +01:00

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1.3 KiB
TypeScript

/**
* Every previously added point is remembered, but new points are added.
* Data coming from upstream will always overwrite a previous value
*/
import FeatureSource, {Tiled} from "../FeatureSource";
import {UIEventSource} from "../../UIEventSource";
import {BBox} from "../../BBox";
export default class RememberingSource implements FeatureSource, Tiled {
public readonly features: UIEventSource<{ feature: any, freshness: Date }[]>;
public readonly name;
public readonly tileIndex: number
public readonly bbox: BBox
constructor(source: FeatureSource & Tiled) {
const self = this;
this.name = "RememberingSource of " + source.name;
this.tileIndex = source.tileIndex
this.bbox = source.bbox;
const empty = [];
this.features = source.features.map(features => {
const oldFeatures = self.features?.data ?? empty;
if (features === undefined) {
return oldFeatures;
}
// Then new ids
const ids = new Set<string>(features.map(f => f.feature.properties.id + f.feature.geometry.type));
// the old data
const oldData = oldFeatures.filter(old => !ids.has(old.feature.properties.id + old.feature.geometry.type))
return [...features, ...oldData];
})
}
}