fix: prevent NPE in event report table-layout download when dimensions/items metadata entries are missing (#23940)

Author: luciano-fiandesio

dhis-2/dhis-services/dhis-service-analytics/src/main/java/org/hisp/dhis/analytics/event/data/EventAggregateService.java

@@ -371,7 +371,7 @@ private void addEventReportDimensionalItems(
           (List<String>)
               ((Map<String, Object>) grid.getMetaData().get(DIMENSIONS.getKey())).get(dimension);
 
-      if (legendOptions.isEmpty()) {
+      if (legendOptions == null || legendOptions.isEmpty()) {
         List<Legend> legends = eventDimensionalItemObject.getLegendSet().getSortedLegends();
         addLegends(dimensionalItems, parentUid, legends);
       } else {
@@ -495,7 +495,7 @@ private Grid generateOutputGrid(
       MetadataItem metadataItem =
           (MetadataItem) ((Map<String, Object>) grid.getMetaData().get(ITEMS.getKey())).get(row);
 
-      String name = defaultIfEmpty(metadataItem.getName(), row);
+      String name = metadataItem == null ? row : defaultIfEmpty(metadataItem.getName(), row);
       String col = defaultIfEmpty(COLUMN_NAMES.get(row), row);
 
       outputGrid.addHeader(new GridHeader(name, col, TEXT, false, true));
@@ -516,7 +516,7 @@ private Grid generateOutputGrid(
               });
 
           String display =
-              builder.length() > 0
+              !builder.isEmpty()
                   ? builder.substring(0, builder.lastIndexOf(DASH_PRETTY_SEPARATOR))
                   : TOTAL_COLUMN_PRETTY_NAME;
 

dhis-2/dhis-services/dhis-service-analytics/src/test/java/org/hisp/dhis/analytics/event/data/EventAggregateServiceTest.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2004-2026, University of Oslo
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors 
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.hisp.dhis.analytics.event.data;
+
+import static org.hisp.dhis.test.TestBase.createDataElement;
+import static org.hisp.dhis.test.TestBase.createLegend;
+import static org.hisp.dhis.test.TestBase.createLegendSet;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.hisp.dhis.analytics.AnalyticsMetaDataKey;
+import org.hisp.dhis.analytics.EventAnalyticsDimensionalItem;
+import org.hisp.dhis.analytics.event.EventQueryParams;
+import org.hisp.dhis.common.Grid;
+import org.hisp.dhis.common.ValueType;
+import org.hisp.dhis.common.ValueTypedDimensionalItemObject;
+import org.hisp.dhis.dataelement.DataElement;
+import org.hisp.dhis.legend.Legend;
+import org.hisp.dhis.legend.LegendSet;
+import org.hisp.dhis.system.grid.ListGrid;
+import org.junit.jupiter.api.Test;
+
+class EventAggregateServiceTest {
+  private final EventAggregateService service =
+      new EventAggregateService(null, null, null, null, null, null, null, null, null, null, null);
+
+  @Test
+  void shouldFallBackToAllLegendsWhenDimensionsMetadataOmitsLegendSetDataElement()
+      throws Exception {
+    Legend legendA = createLegend('A', 0.0, 2.0);
+    Legend legendB = createLegend('B', 2.0, 4.0);
+    LegendSet legendSet = createLegendSet('A', legendA, legendB);
+
+    DataElement dataElement = createDataElement('A');
+    dataElement.setValueType(ValueType.NUMBER);
+    dataElement.setLegendSets(List.of(legendSet));
+
+    Grid grid = new ListGrid();
+    grid.getMetaData().put(AnalyticsMetaDataKey.DIMENSIONS.getKey(), new HashMap<String, Object>());
+
+    List<EventAnalyticsDimensionalItem> dimensionalItems = new ArrayList<>();
+
+    invokeAddEventReportDimensionalItems(dataElement, dimensionalItems, grid, dataElement.getUid());
+
+    assertFalse(dimensionalItems.isEmpty());
+  }
+
+  @Test
+  void shouldNotNpeWhenItemsMetadataOmitsRowDimension() throws Exception {
+    String missingDimensionUid = "deUidAAAAA";
+
+    Grid grid = new ListGrid();
+    grid.getMetaData().put(AnalyticsMetaDataKey.ITEMS.getKey(), new HashMap<String, Object>());
+
+    EventQueryParams params = new EventQueryParams.Builder().build();
+
+    invokeGenerateOutputGrid(grid, params, List.of(), List.of(), List.of(missingDimensionUid));
+  }
+
+  private void invokeAddEventReportDimensionalItems(
+      ValueTypedDimensionalItemObject item,
+      List<EventAnalyticsDimensionalItem> dimensionalItems,
+      Grid grid,
+      String dimension)
+      throws Exception {
+    Method method =
+        EventAggregateService.class.getDeclaredMethod(
+            "addEventReportDimensionalItems",
+            ValueTypedDimensionalItemObject.class,
+            List.class,
+            Grid.class,
+            String.class);
+    method.setAccessible(true);
+    method.invoke(service, item, dimensionalItems, grid, dimension);
+  }
+
+  private Grid invokeGenerateOutputGrid(
+      Grid grid,
+      EventQueryParams params,
+      List<Map<String, EventAnalyticsDimensionalItem>> rowPermutations,
+      List<Map<String, EventAnalyticsDimensionalItem>> columnPermutations,
+      List<String> rowDimensions)
+      throws Exception {
+    Method method =
+        EventAggregateService.class.getDeclaredMethod(
+            "generateOutputGrid",
+            Grid.class,
+            EventQueryParams.class,
+            List.class,
+            List.class,
+            List.class);
+    method.setAccessible(true);
+    return (Grid)
+        method.invoke(service, grid, params, rowPermutations, columnPermutations, rowDimensions);
+  }
+}