JarCastinggeojson-stream
Stream features into and out of GeoJSON objects and Feature Collections. Little more than JSONStream with pre-filled settings.
usage
npm install --save geojson-stream
api
geojsonStream.stringify()
Returns a transform stream that accepts GeoJSON Feature objects and emits a stringified FeatureCollection.
geojsonStream.parse(mapFunc)
Returns a transform stream that accepts a GeoJSON FeatureCollection as a stream and emits Feature objects.
mapFunc(feature, index) is an optional function which takes a Feature, and its zero-based index in the FeatureCollection and returns either a Feature, or null/undefined if the feature should be omitted from output.
example
const geojsonStream = require('geojson-stream');
const fs = require('fs');
const out = fs.createWriteStream('buildings-with-id.geojson');
fs
.createReadStream(`buildings.geojson`)
.pipe(geojsonStream.parse((building, index) => {
if (building.geometry.coordinates === null) {
return null;
}
building.id = index;
return building;
}))
.pipe(geojsonStream.stringify())
.pipe(out);
