Assert that ol.layer.Tile#getUseInterimTilesOnError is always set

src/ol/layer/tilelayer.js

@@ -34,6 +34,9 @@ ol.layer.Tile = function(opt_options) {
   if (!goog.isDef(this.getPreload())) {
     this.setPreload(0);
   }
+  if (!goog.isDef(this.getUseInterimTilesOnError())) {
+    this.setUseInterimTilesOnError(true);
+  }
 };
 goog.inherits(ol.layer.Tile, ol.layer.Layer);
 
@@ -75,12 +78,12 @@ goog.exportProperty(
 
 
 /**
- * @return {boolean|undefined} Use interim tiles on error.
+ * @return {boolean} Use interim tiles on error.
  * @observable
  * @api
  */
 ol.layer.Tile.prototype.getUseInterimTilesOnError = function() {
-  return /** @type {boolean|undefined} */ (
+  return /** @type {boolean} */ (
       this.get(ol.layer.TileProperty.USE_INTERIM_TILES_ON_ERROR));
 };
 goog.exportProperty(
@@ -90,7 +93,7 @@ goog.exportProperty(
 
 
 /**
- * @param {boolean|undefined} useInterimTilesOnError Use interim tiles on error.
+ * @param {boolean} useInterimTilesOnError Use interim tiles on error.
  * @observable
  * @api
  */

src/ol/renderer/canvas/canvastilelayerrenderer.js

@@ -281,9 +281,6 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
       tilesToDrawByZ, getTileIfLoaded);
 
   var useInterimTilesOnError = tileLayer.getUseInterimTilesOnError();
-  if (!goog.isDef(useInterimTilesOnError)) {
-    useInterimTilesOnError = true;
-  }
 
   var tmpExtent = ol.extent.createEmpty();
   var tmpTileRange = new ol.TileRange(0, 0, 0, 0);

src/ol/renderer/dom/domtilelayerrenderer.js

@@ -136,9 +136,6 @@ ol.renderer.dom.TileLayer.prototype.prepareFrame =
       tilesToDrawByZ, getTileIfLoaded);
 
   var useInterimTilesOnError = tileLayer.getUseInterimTilesOnError();
-  if (!goog.isDef(useInterimTilesOnError)) {
-    useInterimTilesOnError = true;
-  }
 
   var tmpExtent = ol.extent.createEmpty();
   var tmpTileRange = new ol.TileRange(0, 0, 0, 0);

src/ol/renderer/webgl/webgltilelayerrenderer.js

@@ -198,10 +198,6 @@ ol.renderer.webgl.TileLayer.prototype.prepareFrame =
         tilesToDrawByZ, getTileIfLoaded);
 
     var useInterimTilesOnError = tileLayer.getUseInterimTilesOnError();
-    if (!goog.isDef(useInterimTilesOnError)) {
-      useInterimTilesOnError = true;
-    }
-
     var allTilesLoaded = true;
     var tmpExtent = ol.extent.createEmpty();
     var tmpTileRange = new ol.TileRange(0, 0, 0, 0);

test/spec/ol/layer/tilelayer.test.js

@@ -24,6 +24,10 @@ describe('ol.layer.Tile', function() {
       expect(layer.getPreload()).to.be(0);
     });
 
+    it('provides default useInterimTilesOnError', function() {
+      expect(layer.getUseInterimTilesOnError()).to.be(true);
+    });
+
   });
 
 });