Merge pull request #11300 from mike-000/patch-2

Drag and Drop to update source and fire event only if features added

src/ol/interaction/DragAndDrop.js

@@ -140,28 +140,27 @@ class DragAndDrop extends Interaction {
     }
 
     const formatConstructors = this.formatConstructors_;
-    let features = [];
     for (let i = 0, ii = formatConstructors.length; i < ii; ++i) {
       const format = new formatConstructors[i]();
-      features = this.tryReadFeatures_(format, result, {
+      const features = this.tryReadFeatures_(format, result, {
         featureProjection: projection,
       });
       if (features && features.length > 0) {
+        if (this.source_) {
+          this.source_.clear();
+          this.source_.addFeatures(features);
+        }
+        this.dispatchEvent(
+          new DragAndDropEvent(
+            DragAndDropEventType.ADD_FEATURES,
+            file,
+            features,
+            projection
+          )
+        );
         break;
       }
     }
-    if (this.source_) {
-      this.source_.clear();
-      this.source_.addFeatures(features);
-    }
-    this.dispatchEvent(
-      new DragAndDropEvent(
-        DragAndDropEventType.ADD_FEATURES,
-        file,
-        features,
-        projection
-      )
-    );
   }
 
   /**
@@ -215,11 +214,14 @@ class DragAndDrop extends Interaction {
    * @param {string} text Text.
    * @param {import("../format/Feature.js").ReadOptions} options Read options.
    * @private
-   * @return {Array<import("../Feature.js").FeatureLike>} Features.
+   * @return {Array<import("../Feature.js").default>} Features.
    */
   tryReadFeatures_(format, text, options) {
     try {
-      return format.readFeatures(text, options);
+      return (
+        /** @type {Array<import("../Feature.js").default>} */
+        (format.readFeatures(text, options))
+      );
     } catch (e) {
       return null;
     }