Files
openlayers/src/ol/io/geojson.js
2013-01-20 00:28:07 -07:00

146 lines
3.7 KiB
JavaScript

goog.provide('ol.io.geojson');
goog.require('ol.geom.Geometry');
goog.require('ol.geom.LineString');
goog.require('ol.geom.MultiLineString');
goog.require('ol.geom.MultiPoint');
goog.require('ol.geom.MultiPolygon');
goog.require('ol.geom.Point');
goog.require('ol.geom.Polygon');
/**
* Parse a GeoJSON string.
* @param {string} str GeoJSON string.
* @return {ol.geom.Geometry|Array.<ol.geom.Geometry>} Parsed geometry or array
* of geometries.
*/
ol.io.geojson.read = function(str) {
// TODO: add options and accept projection
var json = /** @type {GeoJSONObject} */ (JSON.parse(str));
return ol.io.geojson.parse_(json);
};
/**
* @param {GeoJSONObject} json GeoJSON object.
* @return {ol.geom.Geometry|Array.<ol.geom.Geometry>} Parsed geometry or array
* of geometries.
* @private
*/
ol.io.geojson.parse_ = function(json) {
var result;
switch (json.type) {
case 'GeometryCollection':
result = ol.io.geojson.parseGeometryCollection_(
/** @type {GeoJSONGeometryCollection} */ (json));
break;
case 'Point':
result = ol.io.geojson.parsePoint_(
/** @type {GeoJSONGeometry} */ (json));
break;
case 'LineString':
result = ol.io.geojson.parseLineString_(
/** @type {GeoJSONGeometry} */ (json));
break;
case 'Polygon':
result = ol.io.geojson.parsePolygon_(
/** @type {GeoJSONGeometry} */ (json));
break;
case 'MultiPoint':
result = ol.io.geojson.parseMultiPoint_(
/** @type {GeoJSONGeometry} */ (json));
break;
case 'MultiLineString':
result = ol.io.geojson.parseMultiLineString_(
/** @type {GeoJSONGeometry} */ (json));
break;
case 'MultiPolygon':
result = ol.io.geojson.parseMultiPolygon_(
/** @type {GeoJSONGeometry} */ (json));
break;
default:
throw new Error('GeoJSON parsing not implemented for type: ' + json.type);
}
return result;
};
/**
* @param {GeoJSONGeometryCollection} json GeoJSON geometry collection.
* @return {Array.<ol.geom.Geometry>} Parsed array of geometries.
* @private
*/
ol.io.geojson.parseGeometryCollection_ = function(json) {
var geometries = json.geometries,
len = geometries.length,
result = new Array(len),
i;
for (i = 0; i < len; ++i) {
result[i] = ol.io.geojson.parse_(
/** @type {GeoJSONGeometry} */ (geometries[i]));
}
return result;
};
/**
* @param {GeoJSONGeometry} json GeoJSON linestring.
* @return {ol.geom.LineString} Parsed linestring.
* @private
*/
ol.io.geojson.parseLineString_ = function(json) {
return new ol.geom.LineString(json.coordinates);
};
/**
* @param {GeoJSONGeometry} json GeoJSON multi-linestring.
* @return {ol.geom.MultiLineString} Parsed multi-linestring.
* @private
*/
ol.io.geojson.parseMultiLineString_ = function(json) {
return new ol.geom.MultiLineString(json.coordinates);
};
/**
* @param {GeoJSONGeometry} json GeoJSON multi-point.
* @return {ol.geom.MultiPoint} Parsed multi-point.
* @private
*/
ol.io.geojson.parseMultiPoint_ = function(json) {
return new ol.geom.MultiPoint(json.coordinates);
};
/**
* @param {GeoJSONGeometry} json GeoJSON multi-polygon.
* @return {ol.geom.MultiPolygon} Parsed multi-polygon.
* @private
*/
ol.io.geojson.parseMultiPolygon_ = function(json) {
return new ol.geom.MultiPolygon(json.coordinates);
};
/**
* @param {GeoJSONGeometry} json GeoJSON point.
* @return {ol.geom.Point} Parsed multi-point.
* @private
*/
ol.io.geojson.parsePoint_ = function(json) {
return new ol.geom.Point(json.coordinates);
};
/**
* @param {GeoJSONGeometry} json GeoJSON polygon.
* @return {ol.geom.Polygon} Parsed polygon.
* @private
*/
ol.io.geojson.parsePolygon_ = function(json) {
return new ol.geom.Polygon(json.coordinates);
};