[ZEPPELIN-6345] Fire NoteRemove event for each note when deleting a folder

zeppelin-server/src/main/java/org/apache/zeppelin/notebook/NoteManager.java

@@ -288,6 +288,17 @@ public void moveFolder(String folderPath,
     }
   }
 
+  /**
+   * Returns the NoteInfo of all notes under the given folder, without removing them.
+   *
+   * @param folderPath
+   * @return
+   * @throws IOException
+   */
+  public List<NoteInfo> getNoteInfoRecursively(String folderPath) throws IOException {
+    return getFolder(folderPath).getNoteInfoRecursively();
+  }
+
   /**
    * Remove the folder from the tree and returns the affected NoteInfo under this folder.
    *

zeppelin-server/src/main/java/org/apache/zeppelin/notebook/Notebook.java

@@ -552,11 +552,22 @@ public void moveFolder(String folderPath, String newFolderPath, AuthenticationIn
 
   public void removeFolder(String folderPath, AuthenticationInfo subject) throws IOException {
     LOGGER.info("Remove folder {}", folderPath);
-    // TODO(zjffdu) NotebookRepo.remove is called twice here
-    List<NoteInfo> noteInfos = noteManager.removeFolder(folderPath, subject);
+    // Notes must be loaded and their remove listeners fired before the folder (and its
+    // underlying repo storage) is deleted, otherwise the note content is no longer
+    // available to run the same per-note cleanup as removeNote(String, AuthenticationInfo).
+    List<NoteInfo> noteInfos = noteManager.getNoteInfoRecursively(folderPath);
     for (NoteInfo noteInfo : noteInfos) {
-      removeNote(noteInfo.getId(), subject);
+      processNote(noteInfo.getId(),
+        note -> {
+          if (note != null) {
+            note.setRemoved(true);
+            authorizationService.removeNoteAuth(note.getId());
+            fireNoteRemoveEvent(note, subject);
+          }
+          return null;
+        });
     }
+    noteManager.removeFolder(folderPath, subject);
   }
 
   public void emptyTrash(AuthenticationInfo subject) throws IOException {

zeppelin-server/src/test/java/org/apache/zeppelin/notebook/NotebookTest.java

@@ -1701,6 +1701,48 @@ public void onParagraphStatusChange(Paragraph p, Status status) {
     assertEquals(1, onParagraphRemove.get());
   }
 
+  @Test
+  void testRemoveFolderFiresNoteRemoveEventForEachNote() throws IOException {
+    final AtomicInteger onNoteRemove = new AtomicInteger(0);
+    notebook.addNotebookEventListener(new NoteEventListener() {
+      @Override
+      public void onNoteRemove(Note note, AuthenticationInfo subject) {
+        onNoteRemove.incrementAndGet();
+      }
+
+      @Override
+      public void onNoteCreate(Note note, AuthenticationInfo subject) {
+      }
+
+      @Override
+      public void onNoteUpdate(Note note, AuthenticationInfo subject) {
+      }
+
+      @Override
+      public void onParagraphRemove(Paragraph p) {
+      }
+
+      @Override
+      public void onParagraphCreate(Paragraph p) {
+      }
+
+      @Override
+      public void onParagraphUpdate(Paragraph p) {
+      }
+
+      @Override
+      public void onParagraphStatusChange(Paragraph p, Status status) {
+      }
+    });
+
+    notebook.createNote("/folder1/note1", anonymous);
+    notebook.createNote("/folder1/note2", anonymous);
+
+    notebook.removeFolder("/folder1", anonymous);
+
+    assertEquals(2, onNoteRemove.get());
+  }
+
   @Test
   void testGetAllNotes() throws Exception {
     String note1Id = notebook.createNote("note1", anonymous);