Files
openlayers/src/ol/format/GeoJSON.js
2018-09-27 10:00:02 +02:00

532 lines
15 KiB
JavaScript

/**
* @module ol/format/GeoJSON
*/
import {assert} from '../asserts.js';
import Feature from '../Feature.js';
import {transformWithOptions} from '../format/Feature.js';
import JSONFeature from '../format/JSONFeature.js';
import GeometryCollection from '../geom/GeometryCollection.js';
import LineString from '../geom/LineString.js';
import MultiLineString from '../geom/MultiLineString.js';
import MultiPoint from '../geom/MultiPoint.js';
import MultiPolygon from '../geom/MultiPolygon.js';
import Point from '../geom/Point.js';
import Polygon from '../geom/Polygon.js';
import {assign, isEmpty} from '../obj.js';
import {get as getProjection} from '../proj.js';
import GeometryType from '../geom/GeometryType.js';
/**
* @typedef {import("geojson").GeoJSON} GeoJSONObject
* @typedef {import("geojson").Feature} GeoJSONFeature
* @typedef {import("geojson").FeatureCollection} GeoJSONFeatureCollection
* @typedef {import("geojson").Geometry} GeoJSONGeometry
* @typedef {import("geojson").Point} GeoJSONPoint
* @typedef {import("geojson").LineString} GeoJSONLineString
* @typedef {import("geojson").Polygon} GeoJSONPolygon
* @typedef {import("geojson").MultiPoint} GeoJSONMultiPoint
* @typedef {import("geojson").MultiLineString} GeoJSONMultiLineString
* @typedef {import("geojson").MultiPolygon} GeoJSONMultiPolygon
* @typedef {import("geojson").GeometryCollection} GeoJSONGeometryCollection
*/
/**
* @typedef {Object} Options
* @property {import("../proj.js").ProjectionLike} [dataProjection='EPSG:4326'] Default data projection.
* @property {import("../proj.js").ProjectionLike} [featureProjection] Projection for features read or
* written by the format. Options passed to read or write methods will take precedence.
* @property {string} [geometryName] Geometry name to use when creating features.
* @property {boolean} [extractGeometryName=false] Certain GeoJSON providers include
* the geometry_name field in the feature GeoJSON. If set to `true` the GeoJSON reader
* will look for that field to set the geometry name. If both this field is set to `true`
* and a `geometryName` is provided, the `geometryName` will take precedence.
*/
/**
* @classdesc
* Feature format for reading and writing data in the GeoJSON format.
*
* @api
*/
class GeoJSON extends JSONFeature {
/**
* @param {Options=} opt_options Options.
*/
constructor(opt_options) {
const options = opt_options ? opt_options : {};
super();
/**
* @inheritDoc
*/
this.dataProjection = getProjection(
options.dataProjection ?
options.dataProjection : 'EPSG:4326');
if (options.featureProjection) {
this.defaultFeatureProjection = getProjection(options.featureProjection);
}
/**
* Name of the geometry attribute for features.
* @type {string|undefined}
* @private
*/
this.geometryName_ = options.geometryName;
/**
* Look for the geometry name in the feature GeoJSON
* @type {boolean|undefined}
* @private
*/
this.extractGeometryName_ = options.extractGeometryName;
}
/**
* @inheritDoc
*/
readFeatureFromObject(object, opt_options) {
/**
* @type {GeoJSONFeature}
*/
let geoJSONFeature = null;
if (object['type'] === 'Feature') {
geoJSONFeature = /** @type {GeoJSONFeature} */ (object);
} else {
geoJSONFeature = {
'type': 'Feature',
'geometry': /** @type {GeoJSONGeometry} */ (object),
'properties': null
};
}
const geometry = readGeometry(geoJSONFeature['geometry'], opt_options);
const feature = new Feature();
if (this.geometryName_) {
feature.setGeometryName(this.geometryName_);
} else if (this.extractGeometryName_ && 'geometry_name' in geoJSONFeature !== undefined) {
feature.setGeometryName(geoJSONFeature['geometry_name']);
}
feature.setGeometry(geometry);
if ('id' in geoJSONFeature) {
feature.setId(geoJSONFeature['id']);
}
if (geoJSONFeature['properties']) {
feature.setProperties(geoJSONFeature['properties']);
}
return feature;
}
/**
* @inheritDoc
*/
readFeaturesFromObject(object, opt_options) {
const geoJSONObject = /** @type {GeoJSONObject} */ (object);
/** @type {Array<import("../Feature.js").default>} */
let features = null;
if (geoJSONObject['type'] === 'FeatureCollection') {
const geoJSONFeatureCollection = /** @type {GeoJSONFeatureCollection} */ (object);
features = [];
const geoJSONFeatures = geoJSONFeatureCollection['features'];
for (let i = 0, ii = geoJSONFeatures.length; i < ii; ++i) {
features.push(this.readFeatureFromObject(geoJSONFeatures[i], opt_options));
}
} else {
features = [this.readFeatureFromObject(object, opt_options)];
}
return features;
}
/**
* @inheritDoc
*/
readGeometryFromObject(object, opt_options) {
return readGeometry(/** @type {GeoJSONGeometry} */ (object), opt_options);
}
/**
* @inheritDoc
*/
readProjectionFromObject(object) {
const crs = object['crs'];
let projection;
if (crs) {
if (crs['type'] == 'name') {
projection = getProjection(crs['properties']['name']);
} else {
assert(false, 36); // Unknown SRS type
}
} else {
projection = this.dataProjection;
}
return (
/** @type {import("../proj/Projection.js").default} */ (projection)
);
}
/**
* Encode a feature as a GeoJSON Feature object.
*
* @param {import("../Feature.js").default} feature Feature.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONFeature} Object.
* @override
* @api
*/
writeFeatureObject(feature, opt_options) {
opt_options = this.adaptOptions(opt_options);
/** @type {GeoJSONFeature} */
const object = {
'type': 'Feature',
geometry: null,
properties: null
};
const id = feature.getId();
if (id !== undefined) {
object.id = id;
}
const geometry = feature.getGeometry();
if (geometry) {
object.geometry = writeGeometry(geometry, opt_options);
}
const properties = feature.getProperties();
delete properties[feature.getGeometryName()];
if (!isEmpty(properties)) {
object.properties = properties;
}
return object;
}
/**
* Encode an array of features as a GeoJSON object.
*
* @param {Array<import("../Feature.js").default>} features Features.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONFeatureCollection} GeoJSON Object.
* @override
* @api
*/
writeFeaturesObject(features, opt_options) {
opt_options = this.adaptOptions(opt_options);
const objects = [];
for (let i = 0, ii = features.length; i < ii; ++i) {
objects.push(this.writeFeatureObject(features[i], opt_options));
}
return {
type: 'FeatureCollection',
features: objects
};
}
/**
* Encode a geometry as a GeoJSON object.
*
* @param {import("../geom/Geometry.js").default} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry|GeoJSONGeometryCollection} Object.
* @override
* @api
*/
writeGeometryObject(geometry, opt_options) {
return writeGeometry(geometry, this.adaptOptions(opt_options));
}
}
/**
* @param {GeoJSONGeometry|GeoJSONGeometryCollection} object Object.
* @param {import("./Feature.js").ReadOptions=} opt_options Read options.
* @return {import("../geom/Geometry.js").default} Geometry.
*/
function readGeometry(object, opt_options) {
if (!object) {
return null;
}
/**
* @type {import("../geom/Geometry.js").default}
*/
let geometry;
switch (object['type']) {
case GeometryType.POINT: {
geometry = readPointGeometry(/** @type {GeoJSONPoint} */ (object));
break;
}
case GeometryType.LINE_STRING: {
geometry = readLineStringGeometry(/** @type {GeoJSONLineString} */ (object));
break;
}
case GeometryType.POLYGON: {
geometry = readPolygonGeometry(/** @type {GeoJSONPolygon} */ (object));
break;
}
case GeometryType.MULTI_POINT: {
geometry = readMultiPointGeometry(/** @type {GeoJSONMultiPoint} */ (object));
break;
}
case GeometryType.MULTI_LINE_STRING: {
geometry = readMultiLineStringGeometry(/** @type {GeoJSONMultiLineString} */ (object));
break;
}
case GeometryType.MULTI_POLYGON: {
geometry = readMultiPolygonGeometry(/** @type {GeoJSONMultiPolygon} */ (object));
break;
}
case GeometryType.GEOMETRY_COLLECTION: {
geometry = readGeometryCollectionGeometry(/** @type {GeoJSONGeometryCollection} */ (object));
break;
}
default: {
throw new Error('Unsupported GeoJSON type: ' + object.type);
}
}
return /** @type {import("../geom/Geometry.js").default} */ (transformWithOptions(geometry, false, opt_options));
}
/**
* @param {GeoJSONGeometryCollection} object Object.
* @param {import("./Feature.js").ReadOptions=} opt_options Read options.
* @return {GeometryCollection} Geometry collection.
*/
function readGeometryCollectionGeometry(object, opt_options) {
const geometries = object['geometries'].map(
/**
* @param {GeoJSONGeometry} geometry Geometry.
* @return {import("../geom/Geometry.js").default} geometry Geometry.
*/
function(geometry) {
return readGeometry(geometry, opt_options);
});
return new GeometryCollection(geometries);
}
/**
* @param {GeoJSONPoint} object Object.
* @return {Point} Point.
*/
function readPointGeometry(object) {
return new Point(object['coordinates']);
}
/**
* @param {GeoJSONLineString} object Object.
* @return {LineString} LineString.
*/
function readLineStringGeometry(object) {
return new LineString(object['coordinates']);
}
/**
* @param {GeoJSONMultiLineString} object Object.
* @return {MultiLineString} MultiLineString.
*/
function readMultiLineStringGeometry(object) {
return new MultiLineString(object['coordinates']);
}
/**
* @param {GeoJSONMultiPoint} object Object.
* @return {MultiPoint} MultiPoint.
*/
function readMultiPointGeometry(object) {
return new MultiPoint(object['coordinates']);
}
/**
* @param {GeoJSONMultiPolygon} object Object.
* @return {MultiPolygon} MultiPolygon.
*/
function readMultiPolygonGeometry(object) {
return new MultiPolygon(object['coordinates']);
}
/**
* @param {GeoJSONPolygon} object Object.
* @return {Polygon} Polygon.
*/
function readPolygonGeometry(object) {
return new Polygon(object['coordinates']);
}
/**
* @param {import("../geom/Geometry.js").default} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writeGeometry(geometry, opt_options) {
geometry = /** @type {import("../geom/Geometry.js").default} */ (transformWithOptions(geometry, true, opt_options));
const type = geometry.getType();
/** @type {GeoJSONGeometry} */
let geoJSON;
switch (type) {
case GeometryType.POINT: {
geoJSON = writePointGeometry(/** @type {Point} */ (geometry), opt_options);
break;
}
case GeometryType.LINE_STRING: {
geoJSON = writeLineStringGeometry(/** @type {LineString} */ (geometry), opt_options);
break;
}
case GeometryType.POLYGON: {
geoJSON = writePolygonGeometry(/** @type {Polygon} */ (geometry), opt_options);
break;
}
case GeometryType.MULTI_POINT: {
geoJSON = writeMultiPointGeometry(/** @type {MultiPoint} */ (geometry), opt_options);
break;
}
case GeometryType.MULTI_LINE_STRING: {
geoJSON = writeMultiLineStringGeometry(/** @type {MultiLineString} */ (geometry), opt_options);
break;
}
case GeometryType.MULTI_POLYGON: {
geoJSON = writeMultiPolygonGeometry(/** @type {MultiPolygon} */ (geometry), opt_options);
break;
}
case GeometryType.GEOMETRY_COLLECTION: {
geoJSON = writeGeometryCollectionGeometry(/** @type {GeometryCollection} */ (geometry), opt_options);
break;
}
case GeometryType.CIRCLE: {
geoJSON = {
type: 'GeometryCollection',
geometries: []
};
break;
}
default: {
throw new Error('Unsupported geometry type: ' + type);
}
}
return geoJSON;
}
/**
* @param {GeometryCollection} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometryCollection} GeoJSON geometry collection.
*/
function writeGeometryCollectionGeometry(geometry, opt_options) {
const geometries = geometry.getGeometriesArray().map(function(geometry) {
const options = assign({}, opt_options);
delete options.featureProjection;
return writeGeometry(geometry, options);
});
return {
type: 'GeometryCollection',
geometries: geometries
};
}
/**
* @param {LineString} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writeLineStringGeometry(geometry, opt_options) {
return {
type: 'LineString',
coordinates: geometry.getCoordinates()
};
}
/**
* @param {MultiLineString} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writeMultiLineStringGeometry(geometry, opt_options) {
return {
type: 'MultiLineString',
coordinates: geometry.getCoordinates()
};
}
/**
* @param {MultiPoint} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writeMultiPointGeometry(geometry, opt_options) {
return {
type: 'MultiPoint',
coordinates: geometry.getCoordinates()
};
}
/**
* @param {MultiPolygon} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writeMultiPolygonGeometry(geometry, opt_options) {
let right;
if (opt_options) {
right = opt_options.rightHanded;
}
return {
type: 'MultiPolygon',
coordinates: geometry.getCoordinates(right)
};
}
/**
* @param {Point} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writePointGeometry(geometry, opt_options) {
return {
type: 'Point',
coordinates: geometry.getCoordinates()
};
}
/**
* @param {Polygon} geometry Geometry.
* @param {import("./Feature.js").WriteOptions=} opt_options Write options.
* @return {GeoJSONGeometry} GeoJSON geometry.
*/
function writePolygonGeometry(geometry, opt_options) {
let right;
if (opt_options) {
right = opt_options.rightHanded;
}
return {
type: 'Polygon',
coordinates: geometry.getCoordinates(right)
};
}
export default GeoJSON;