Extending FeatureLoader type and refactoring loadFeaturesXhr

src/ol/featureloader.js

@@ -16,15 +16,19 @@ let withCredentials = false;
  * load features.
  *
  * This function takes an {@link module:ol/extent~Extent} representing the area to be loaded,
- * a `{number}` representing the resolution (map units per pixel) and an
- * {@link module:ol/proj/Projection} for the projection  as
+ * a `{number}` representing the resolution (map units per pixel), an
+ * {@link module:ol/proj/Projection} for the projection and success and failure callbacks as
  * arguments. `this` within the function is bound to the
  * {@link module:ol/source/Vector} it's called from.
  *
  * The function is responsible for loading the features and adding them to the
  * source.
- * @typedef {function(this:(import("./source/Vector").default|import("./VectorTile.js").default), import("./extent.js").Extent, number,
- *                    import("./proj/Projection.js").default): void} FeatureLoader
+ * @typedef {function(this:(import("./source/Vector").default|import("./VectorTile.js").default),
+ *           import("./extent.js").Extent,
+ *           number,
+ *           import("./proj/Projection.js").default,
+ *           function(): void=,
+ *           function(): void=): void} FeatureLoader
  * @api
  */
 
@@ -43,23 +47,23 @@ let withCredentials = false;
 /**
  * @param {string|FeatureUrlFunction} url Feature URL service.
  * @param {import("./format/Feature.js").default} format Feature format.
- * @param {function(this:import("./VectorTile.js").default, Array<import("./Feature.js").default>, import("./proj/Projection.js").default, import("./extent.js").Extent): void|function(this:import("./source/Vector").default, Array<import("./Feature.js").default>): void} success
- *     Function called with the loaded features and optionally with the data
- *     projection. Called with the vector tile or source as `this`.
- * @param {function(this:import("./VectorTile.js").default): void|function(this:import("./source/Vector").default): void} failure
- *     Function called when loading failed. Called with the vector tile or
- *     source as `this`.
- * @return {FeatureLoader} The feature loader.
- */
-export function loadFeaturesXhr(url, format, success, failure) {
-  return (
-    /**
  * @param {import("./extent.js").Extent} extent Extent.
  * @param {number} resolution Resolution.
  * @param {import("./proj/Projection.js").default} projection Projection.
-     * @this {import("./source/Vector").default|import("./VectorTile.js").default}
+ * @param {function(Array<import("./Feature.js").default>, import("./proj/Projection.js").default): void} success Success
+ *      Function called with the loaded features and optionally with the data projection.
+ * @param {function(): void} failure Failure
+ *      Function called when loading failed.
  */
-    function (extent, resolution, projection) {
+export function loadFeaturesXhr(
+  url,
+  format,
+  extent,
+  resolution,
+  projection,
+  success,
+  failure
+) {
   const xhr = new XMLHttpRequest();
   xhr.open(
     'GET',
@@ -94,30 +98,26 @@ export function loadFeaturesXhr(url, format, success, failure) {
         source = /** @type {ArrayBuffer} */ (xhr.response);
       }
       if (source) {
-            success.call(
-              this,
-              format.readFeatures(source, {
+        success(
+          /** @type {Array<import("./Feature.js").default>} */
+          (format.readFeatures(source, {
             extent: extent,
             featureProjection: projection,
-              }),
+          })),
           format.readProjection(source)
         );
       } else {
-            failure.call(this);
+        failure();
       }
     } else {
-          failure.call(this);
+      failure();
     }
-      }.bind(this);
+  };
   /**
    * @private
    */
-      xhr.onerror = function () {
-        failure.call(this);
-      }.bind(this);
+  xhr.onerror = failure;
   xhr.send();
-    }
-  );
 }
 
 /**
@@ -130,25 +130,35 @@ export function loadFeaturesXhr(url, format, success, failure) {
  * @api
  */
 export function xhr(url, format) {
-  return loadFeaturesXhr(
+  /**
+   * @param {import("./extent.js").Extent} extent Extent.
+   * @param {number} resolution Resolution.
+   * @param {import("./proj/Projection.js").default} projection Projection.
+   * @param {function(): void} success Success
+   *      Function called when loading succeeded.
+   * @param {function(): void} failure Failure
+   *      Function called when loading failed.
+   * @this {import("./source/Vector").default}
+   */
+  return function (extent, resolution, projection, success, failure) {
+    const sourceOrTile = /** @type {import("./source/Vector").default} */ (this);
+    loadFeaturesXhr(
       url,
       format,
+      extent,
+      resolution,
+      projection,
       /**
        * @param {Array<import("./Feature.js").default>} features The loaded features.
        * @param {import("./proj/Projection.js").default} dataProjection Data
        * projection.
-     * @this {import("./source/Vector").default|import("./VectorTile.js").default}
        */
       function (features, dataProjection) {
-      const sourceOrTile = /** @type {?} */ (this);
-      if (typeof sourceOrTile.addFeatures === 'function') {
-        /** @type {import("./source/Vector").default} */ (sourceOrTile).addFeatures(
-          features
-        );
-      }
+        sourceOrTile.addFeatures(features);
       },
       /* FIXME handle error */ VOID
     );
+  };
 }
 
 /**

src/ol/source/VectorTile.js

@@ -528,11 +528,22 @@ export default VectorTile;
  * @param {string} url URL.
  */
 export function defaultLoadFunction(tile, url) {
-  const loader = loadFeaturesXhr(
+  tile.setLoader(
+    /**
+     * @param {import("../extent.js").Extent} extent Extent.
+     * @param {number} resolution Resolution.
+     * @param {import("../proj/Projection.js").default} projection Projection.
+     */
+    function (extent, resolution, projection) {
+      loadFeaturesXhr(
         url,
         tile.getFormat(),
+        extent,
+        resolution,
+        projection,
         tile.onLoad.bind(tile),
         tile.onError.bind(tile)
       );
-  tile.setLoader(loader);
+    }
+  );
 }