39 lines
1.2 KiB
TypeScript
39 lines
1.2 KiB
TypeScript
import * as fs from "fs"
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function main(args) {
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if (args.length < 2) {
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console.log(
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"Given a single geojson file and an attribute-key, will generate a new file for every value of the partition."
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)
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console.log("USAGE: perProperty `file.geojson` `property-key`")
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return
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}
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const path = args[0]
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const key = args[1]
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const data = JSON.parse(fs.readFileSync(path, { encoding: "utf8" }))
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const perProperty = new Map<string, any[]>()
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console.log("Partitioning", data.features.length, "features")
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for (const feature of data.features) {
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const v = feature.properties[key]
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if (!perProperty.has(v)) {
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console.log("Found a new category:", v)
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perProperty.set(v, [])
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}
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perProperty.get(v).push(feature)
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}
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const stripped = path.substr(0, path.length - ".geojson".length)
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perProperty.forEach((features, v) => {
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fs.writeFileSync(
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stripped + "." + v.replace(/[^a-zA-Z0-9_]/g, "_") + ".geojson",
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JSON.stringify({
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type: "FeatureCollection",
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features,
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})
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)
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})
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}
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main(process.argv.slice(2))
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