Add geojson module in io package

base.json

@@ -39,7 +39,9 @@
   "disambiguate-properties": true,
 
   "externs": [
+    "//json.js",
     "externs/bingmaps.js",
+    "externs/geojson.js",
     "externs/proj4js.js",
     "externs/tilejson.js"
   ],

externs/geojson.js

@@ -6,17 +6,29 @@
  */
 
 
-
 /**
  * @constructor
  */
-var GeoJSONCRS = function() {};
+var GeoJSONObject = function() {};
 
 
 /**
  * @type {string}
  */
-GeoJSONCRS.prototype.type;
+GeoJSONObject.prototype.type;
+
+
+/**
+ * @type {!GeoJSONCRS|undefined}
+ */
+GeoJSONObject.prototype.crs;
+
+
+/**
+ * @constructor
+ * @extends {GeoJSONObject}
+ */
+var GeoJSONCRS = function() {};
 
 
 /**
@@ -28,35 +40,38 @@ GeoJSONCRS.prototype.properties;
 
 /**
  * @constructor
+ * @extends {GeoJSONObject}
  */
 var GeoJSONGeometry = function() {};
 
 
 /**
- * @type {string}
- */
-GeoJSONGeometry.prototype.type;
-
-
-/**
- * @type {!Array.<number>|!Array.<!Array.<number>>}
+ * @type {!Array.<number>|!Array.<!Array.<number>>|
+ *        !Array.<!Array.<!Array.<number>>>}
  */
 GeoJSONGeometry.prototype.coordinates;
 
 
+/**
+ * @constructor
+ * @extends {GeoJSONObject}
+ */
+var GeoJSONGeometryCollection = function() {};
+
+
+/**
+ * @type {!Array.<GeoJSONGeometry>}
+ */
+GeoJSONGeometryCollection.prototype.geometries;
+
 
 /**
  * @constructor
+ * @extends {GeoJSONObject}
  */
 var GeoJSONFeature = function() {};
 
 
-/**
- * @type {string}
- */
-GeoJSONFeature.prototype.type;
-
-
 /**
  * @type {GeoJSONGeometry}
  */
@@ -72,16 +87,11 @@ GeoJSONFeature.prototype.properties;
 
 /**
  * @constructor
+ * @extends {GeoJSONObject}
  */
 var GeoJSONFeatureCollection = function() {};
 
 
-/**
- * @type {string}
- */
-GeoJSONFeatureCollection.prototype.type;
-
-
 /**
  * @type {!Array.<GeoJSONFeature>}
  */
@@ -94,13 +104,3 @@ GeoJSONFeatureCollection.prototype.features;
 GeoJSONFeatureCollection.prototype.bbox;
 
 
-/**
- * @type {!GeoJSONCRS|undefined}
- */
-GeoJSONFeatureCollection.prototype.crs;
-
-
-/**
- * @type {!Object.<string, *>}
- */
-GeoJSONFeatureCollection.prototype.properties;

src/ol/io/geojson.js

@@ -0,0 +1,145 @@
+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);
+};

test/ol.html

@@ -80,6 +80,7 @@
   <script type="text/javascript" src="spec/ol/rectangle.test.js"></script>
   <script type="text/javascript" src="spec/ol/resolutionconstraint.test.js"></script>
   <script type="text/javascript" src="spec/ol/view2d.test.js"></script>
+  <script type="text/javascript" src="spec/ol/io/geojson.test.js"></script>
   <script type="text/javascript" src="spec/ol/geom/linearring.test.js"></script>
   <script type="text/javascript" src="spec/ol/geom/linestring.test.js"></script>
   <script type="text/javascript" src="spec/ol/geom/point.test.js"></script>

test/spec/ol/io/geojson.test.js

@@ -0,0 +1,65 @@
+describe('ol.io.geojson', function() {
+
+  describe('read()', function() {
+
+    it('parses point', function() {
+      var str = JSON.stringify({
+        type: 'Point',
+        coordinates: [10, 20]
+      });
+
+      var obj = ol.io.geojson.read(str);
+      expect(obj).toBeA(ol.geom.Point);
+      expect(obj.coordinates[0]).toBe(10);
+      expect(obj.coordinates[1]).toBe(20);
+    });
+
+    it('parses linestring', function() {
+      var str = JSON.stringify({
+        type: 'LineString',
+        coordinates: [[10, 20], [30, 40]]
+      });
+
+      var obj = ol.io.geojson.read(str);
+      expect(obj).toBeA(ol.geom.LineString);
+      expect(obj.coordinates[0]).toBe(10);
+      expect(obj.coordinates[1]).toBe(20);
+      expect(obj.coordinates[2]).toBe(30);
+      expect(obj.coordinates[3]).toBe(40);
+    });
+
+    it('parses polygon', function() {
+      var outer = [[0, 0], [10, 0], [10, 10], [0, 10], [0, 0]],
+          inner1 = [[1, 1], [2, 1], [2, 2], [1, 2], [1, 1]],
+          inner2 = [[8, 8], [9, 8], [9, 9], [8, 9], [8, 8]],
+          str = JSON.stringify({
+            type: 'Polygon',
+            coordinates: [outer, inner1, inner2]
+          });
+
+      var obj = ol.io.geojson.read(str);
+      expect(obj).toBeA(ol.geom.Polygon);
+      expect(obj.rings.length).toBe(3);
+      expect(obj.rings[0]).toBeA(ol.geom.LinearRing);
+      expect(obj.rings[1]).toBeA(ol.geom.LinearRing);
+      expect(obj.rings[2]).toBeA(ol.geom.LinearRing);
+    });
+
+    it('parses geometry collection', function() {
+      var str = JSON.stringify({
+        type: 'GeometryCollection',
+        geometries: [
+          {type: 'Point', coordinates: [10, 20]},
+          {type: 'LineString', coordinates: [[30, 40], [50, 60]]}
+        ]
+      });
+
+      var array = ol.io.geojson.read(str);
+      expect(array.length).toBe(2);
+      expect(array[0]).toBeA(ol.geom.Point);
+      expect(array[1]).toBeA(ol.geom.LineString);
+    });
+
+  });
+
+});