osm-flatten-relation

Resolve an OpenStreetMap relation recursively.

Installing

npm install osm-flatten-relation

Usage

From the command line:

osm-flatten-relation 2679163 >nodes.ndjson

As a JavaScript library:

import {flattenOsmRelation as flatten} from 'osm-flatten-relation'

flatten(relation, concurrency = 4, retries = 3)
.on('stats', (stats) => console.log(stats))
.on('relation', (relation) => console.log('relation', relation.id))
.on('way', (way) => console.log('way', way.id))
.on('node', (node) => console.log('node', node.id))
// .on('data', console.log)
.on('error', console.error)

flatten returns a readable stream of a relation's ways and nodes. It will also emit the events relation, way and node whenever it fetched data.

Note: With concurrency > 1, nodes will not be emitted in breadth-first order anymore.

Example

To get all nodes of U-Bahnlinie U6: Alt-Mariendorf => Alt-Tegel with a concurrency of 5 requests:

import {flattenOsmRelation as flatten} from 'osm-flatten-relation'

flatten(2679163, 5)
.on('data', console.log)
.once('erorr', (err) => {
	console.log(err)
	process.exit(1)
})

{id: 3043920508, latitude: 52.439691,  longitude: 13.3877031}
{id: 31034998,   latitude: 52.4537104, longitude: 13.3843233}
// …
{id: 1688279730, latitude: 52.439011,  longitude: 13.3878563}

Contributing

If you have a question, found a bug or want to propose a feature, have a look at the issues page.