mapcomplete/Logic/FeatureSource/Sources/RememberingSource.ts

37 lines
1.4 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 { Store, UIEventSource } from "../../UIEventSource"
import { BBox } from "../../BBox"
export default class RememberingSource implements FeatureSource, Tiled {
public readonly features: Store<{ 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 = []
const featureSource = new UIEventSource<{ feature: any; freshness: Date }[]>(empty)
this.features = featureSource
source.features.addCallbackAndRunD((features) => {
const oldFeatures = self.features?.data ?? empty
// 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)
)
featureSource.setData([...features, ...oldData])
})
}
}