ol-ext/format/GeoJSONP.js

A set of cool extensions for OpenLayers (ol) in node modules structure

import ol_format_GeoJSONX from './GeoJSONX.js'
import ol_format_Polyline from 'ol/format/Polyline.js'
import ol_geom_Point from 'ol/geom/Point.js'
import ol_geom_LineString from 'ol/geom/LineString.js'

/** Feature format for reading and writing data in the GeoJSONP format,
 * using Polyline Algorithm to encode geometry.
 * @constructor 
 * @extends {ol_format_GeoJSON}
 * @param {*} options options.
 *  @param {number} options.decimals number of decimals to save, default 6
 *  @param {ol.ProjectionLike} options.dataProjection Projection of the data we are reading. If not provided `EPSG:4326`
 *  @param {ol.ProjectionLike} options.featureProjection Projection of the feature geometries created by the format reader. If not provided, features will be returned in the dataProjection.
 */
var ol_format_GeoJSONP = class olformatGeoJSONP extends ol_format_GeoJSONX {
  constructor(options) {
    options = options || {}
    super(options)

    this._lineFormat = new ol_format_Polyline({ factor: Math.pow(10, options.decimals || 6) })
  }
  /** Encode coordinates
   * @param {ol.coordinate|Array<ol.coordinate>} v
   * @return {string|Array<string>}
   * @api
   */
  encodeCoordinates(v) {
    var g
    if (typeof (v[0]) === 'number') {
      g = new ol_geom_Point(v)
      return this._lineFormat.writeGeometry(g)
    } else if (v.length && v[0]) {
      var tab = (typeof (v[0][0]) === 'number')
      if (tab) {
        g = new ol_geom_LineString(v)
        return this._lineFormat.writeGeometry(g)
      } else {
        var r = []
        for (var i = 0; i < v.length; i++) {
          r[i] = this.encodeCoordinates(v[i])
        }
        return r
      }
    } else {
      return this.encodeCoordinates([0, 0])
    }
  }
  /** Decode coordinates
   * @param {string|Array<string>}
   * @return {ol.coordinate|Array<ol.coordinate>} v
   * @api
   */
  decodeCoordinates(v) {
    var i, g
    if (typeof (v) === 'string') {
      g = this._lineFormat.readGeometry(v)
      return g.getCoordinates()[0]
    } else if (v.length) {
      var tab = (typeof (v[0]) === 'string')
      var r = []
      if (tab) {
        for (i = 0; i < v.length; i++) {
          g = this._lineFormat.readGeometry(v[i])
          r[i] = g.getCoordinates()
        }
      } else {
        for (i = 0; i < v.length; i++) {
          r[i] = this.decodeCoordinates(v[i])
        }
      }
      return r
    } else {
      return null
    }
  }
}

export default ol_format_GeoJSONP