Add transformGeometry function to avoid repeated code

src/ol/format/featureformat.js

@@ -1,6 +1,7 @@
 goog.provide('ol.format.Feature');
 
 goog.require('goog.functions');
+goog.require('ol.proj');
 
 
 
@@ -98,3 +99,28 @@ ol.format.Feature.prototype.writeFeatures = goog.abstractMethod;
  * @return {ArrayBuffer|Node|Object|string} Node.
  */
 ol.format.Feature.prototype.writeGeometry = goog.abstractMethod;
+
+
+/**
+ * @param {ol.geom.Geometry} geometry Geometry.
+ * @param {boolean} write Set to true for writing, false for reading.
+ * @param {(olx.format.WriteOptions|olx.format.ReadOptions)=} opt_options
+ *     Options.
+ * @return {ol.geom.Geometry} Transformed geometry.
+ * @protected
+ */
+ol.format.Feature.transformGeometry = function(
+    geometry, write, opt_options) {
+  var featureProjection = goog.isDef(opt_options) ?
+      ol.proj.get(opt_options.featureProjection) : null;
+  var dataProjection = goog.isDef(opt_options) ?
+      ol.proj.get(opt_options.dataProjection) : null;
+  if (!goog.isNull(featureProjection) && !goog.isNull(dataProjection) &&
+      !ol.proj.equivalent(featureProjection, dataProjection)) {
+    return (write ? geometry.clone() : geometry).transform(
+        write ? featureProjection : dataProjection,
+        write ? dataProjection : featureProjection);
+  } else {
+    return geometry;
+  }
+};

src/ol/format/geojsonformat.js

@@ -7,6 +7,7 @@ goog.require('goog.array');
 goog.require('goog.asserts');
 goog.require('goog.object');
 goog.require('ol.Feature');
+goog.require('ol.format.Feature');
 goog.require('ol.format.JSONFeature');
 goog.require('ol.geom.GeometryCollection');
 goog.require('ol.geom.GeometryType');
@@ -72,18 +73,10 @@ ol.format.GeoJSON.readGeometry_ = function(object, opt_options) {
   if (goog.isNull(object)) {
     return null;
   }
-  var featureProjection = goog.isDef(opt_options) ?
-      ol.proj.get(opt_options.featureProjection) : null;
-  var dataProjection = goog.isDef(opt_options) ?
-      ol.proj.get(opt_options.dataProjection) : null;
   var geometryReader = ol.format.GeoJSON.GEOMETRY_READERS_[object.type];
   goog.asserts.assert(goog.isDef(geometryReader));
-  var geometry = geometryReader(object);
+  return ol.format.Feature.transformGeometry(
-  if (!goog.isNull(featureProjection) && !goog.isNull(dataProjection) &&
+      geometryReader(object), false, opt_options);
-      !ol.proj.equivalent(featureProjection, dataProjection)) {
-    geometry.transform(dataProjection, featureProjection);
-  }
-  return geometry;
 };
 
 
@@ -183,17 +176,8 @@ ol.format.GeoJSON.readPolygonGeometry_ = function(object) {
 ol.format.GeoJSON.writeGeometry_ = function(geometry, opt_options) {
   var geometryWriter = ol.format.GeoJSON.GEOMETRY_WRITERS_[geometry.getType()];
   goog.asserts.assert(goog.isDef(geometryWriter));
-  var featureProjection = goog.isDef(opt_options) ?
+  return geometryWriter(
-      ol.proj.get(opt_options.featureProjection) : null;
+      ol.format.Feature.transformGeometry(geometry, true, opt_options));
-  var dataProjection = goog.isDef(opt_options) ?
-      ol.proj.get(opt_options.dataProjection) : featureProjection;
-  if (!goog.isNull(featureProjection) && !goog.isNull(dataProjection) &&
-      !ol.proj.equivalent(featureProjection, dataProjection)) {
-    return geometryWriter(
-        geometry.clone().transform(featureProjection, dataProjection));
-  } else {
-    return geometryWriter(geometry);
-  }
 };