Add a writeStyles option to KML format

externs/olx.js

@@ -1796,7 +1796,8 @@ olx.format.IGCOptions.prototype.altitudeMode;
 /**
  * @typedef {{extractStyles: (boolean|undefined),
  *     defaultStyle: (Array.<ol.style.Style>|undefined),
- *     showPointNames: (boolean|undefined)}}
+ *     showPointNames: (boolean|undefined),
+ *     writeStyles: (boolean|undefined)}}
  * @api
  */
 olx.format.KMLOptions;
@@ -1826,6 +1827,14 @@ olx.format.KMLOptions.prototype.showPointNames;
 olx.format.KMLOptions.prototype.defaultStyle;
 
 
+/**
+ * Write styles into KML. Default is `true`.
+ * @type {boolean|undefined}
+ * @api stable
+ */
+olx.format.KMLOptions.prototype.writeStyles;
+
+
 /**
  * @typedef {{featureNS: (Object.<string, string>|string|undefined),
  *     featureType: (Array.<string>|string|undefined),

src/ol/format/kmlformat.js

@@ -92,6 +92,13 @@ ol.format.KML = function(opt_options) {
   this.extractStyles_ = options.extractStyles !== undefined ?
       options.extractStyles : true;
 
+  /**
+   * @private
+   * @type {boolean}
+   */
+  this.writeStyles_ = options.writeStyles !== undefined ?
+      options.writeStyles : true;
+
   /**
    * @private
    * @type {Object.<string, (Array.<ol.style.Style>|string)>}
@@ -2169,6 +2176,7 @@ ol.format.KML.writeCoordinatesTextNode_ =
  * @param {Node} node Node.
  * @param {Array.<ol.Feature>} features Features.
  * @param {Array.<*>} objectStack Object stack.
+ * @this {ol.format.KML}
  * @private
  */
 ol.format.KML.writeDocument_ = function(node, features, objectStack) {
@@ -2366,6 +2374,7 @@ ol.format.KML.writeBoundaryIs_ = function(node, linearRing, objectStack) {
  * @param {Node} node Node.
  * @param {ol.Feature} feature Feature.
  * @param {Array.<*>} objectStack Object stack.
+ * @this {ol.format.KML}
  * @private
  */
 ol.format.KML.writePlacemark_ = function(node, feature, objectStack) {
@@ -2378,14 +2387,18 @@ ol.format.KML.writePlacemark_ = function(node, feature, objectStack) {
 
   // serialize properties (properties unknown to KML are not serialized)
   var properties = feature.getProperties();
+
   var styleFunction = feature.getStyleFunction();
   if (styleFunction) {
     // FIXME the styles returned by the style function are supposed to be
     // resolution-independent here
     var styles = styleFunction.call(feature, 0);
     if (styles && styles.length > 0) {
+      var style = styles[0];
+      if (this.writeStyles_) {
         properties['Style'] = styles[0];
-      var textStyle = styles[0].getText();
+      }
+      var textStyle = style.getText();
       if (textStyle) {
         properties['name'] = textStyle.getText();
       }
@@ -2988,6 +3001,7 @@ ol.format.KML.prototype.writeFeaturesNode = function(features, opt_options) {
   var orderedKeys = ol.format.KML.KML_SEQUENCE_[kml.namespaceURI];
   var values = ol.xml.makeSequence(properties, orderedKeys);
   ol.xml.pushSerializeAndPop(context, ol.format.KML.KML_SERIALIZERS_,
-      ol.xml.OBJECT_PROPERTY_NODE_FACTORY, values, [opt_options], orderedKeys);
+      ol.xml.OBJECT_PROPERTY_NODE_FACTORY, values, [opt_options], orderedKeys,
+      this);
   return kml;
 };

test/spec/ol/format/kmlformat.test.js

@@ -1779,6 +1779,28 @@ describe('ol.format.KML', function() {
         expect(node).to.xmleql(ol.xml.parse(text));
       });
 
+      it('does not write styles when writeStyles option is false', function() {
+        format = new ol.format.KML({writeStyles: false});
+        var style = new ol.style.Style({
+          image: new ol.style.Icon({
+            src: 'http://foo.png'
+          })
+        });
+        var feature = new ol.Feature();
+        feature.setStyle([style]);
+        var node = format.writeFeaturesNode([feature]);
+        var text =
+            '<kml xmlns="http://www.opengis.net/kml/2.2"' +
+            ' xmlns:gx="http://www.google.com/kml/ext/2.2"' +
+            ' xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"' +
+            ' xsi:schemaLocation="http://www.opengis.net/kml/2.2' +
+            ' https://developers.google.com/kml/schema/kml22gx.xsd">' +
+            '  <Placemark>' +
+            '  </Placemark>' +
+            '</kml>';
+        expect(node).to.xmleql(ol.xml.parse(text));
+      });
+
       it('can write an feature\'s text style', function() {
         var style = new ol.style.Style({
           text: new ol.style.Text({