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