overpass-frontend/src/evaluator/meta.js

A JavaScript (NodeJS/Browser) library to easily access data from OpenStreetMap via Overpass API or from an OSM File. The objects can directly be used with LeafletJS or exported to GeoJSON. Data will be cached in the browser memory.

const EvaluatorFunction = require('../EvaluatorFunction')
const OverpassFrontend = require('../defines')

module.exports = class EvaluatorFunctionMeta extends EvaluatorFunction {
  constructor (fun, parameters) {
    super(fun, parameters)
    if (['id', 'type'].includes(this.fun)) {
      this.requestProperties = OverpassFrontend.ID_ONLY
    } else {
      this.requestProperties = OverpassFrontend.META
    }
  }

  eval (context) {
    switch (this.fun) {
      case 'id': return context.osm_id
      case 'type': return context.type
      case 'version': return context.meta && context.meta.version
      case 'timestamp': return context.meta && context.meta.timestamp
      case 'changeset': return context.meta && context.meta.changeset
      case 'uid': return context.meta && context.meta.uid
      case 'user': return context.meta && context.meta.user
    }
  }

  compileLokiJS () {
    switch (this.fun) {
      case 'id': return { osm_id: { $exists: true } }
      case 'type': return { type: { $exists: true } }
      case 'version': return { 'osmMeta.version': { $exists: true } }
      case 'timestamp': return { 'osmMeta.timestamp': { $exists: true } }
      case 'changeset': return { 'osmMeta.changeset': { $exists: true } }
      case 'uid': return { 'osmMeta.uid': { $exists: true } }
      case 'user': return { 'osmMeta.user': { $exists: true } }
    }
  }
}