[release-11.6.3] Geomap: Require layer to have data for legend (#106228)

* Geomap: Require layer to have data for legend (#105580)

(cherry picked from commit 16a6d61ca7)

* Remove test for non-existent function

* Sync up go work sum

* Remove unused import

public/app/plugins/panel/geomap/GeomapPanel.tsx

@@ -31,7 +31,7 @@ import { getActions } from './utils/actions';
 import { getLayersExtent } from './utils/getLayersExtent';
 import { applyLayerFilter, initLayer } from './utils/layers';
 import { pointerClickListener, pointerMoveListener, setTooltipListeners } from './utils/tooltip';
-import { updateMap, getNewOpenLayersMap, notifyPanelEditor } from './utils/utils';
+import { updateMap, getNewOpenLayersMap, notifyPanelEditor, hasLayerData } from './utils/utils';
 import { centerPointRegistry, MapCenterID } from './view';
 
 // Allows multiple panels to share the same view instance
@@ -182,6 +182,9 @@ export class GeomapPanel extends Component<Props, State> {
         this.map.setView(view);
       }
     }
+
+    // Update legends when data changes
+    this.setState({ legends: this.getLegends() });
   }
 
   initMapRef = async (div: HTMLDivElement) => {
@@ -366,9 +369,12 @@ export class GeomapPanel extends Component<Props, State> {
     const legends: ReactNode[] = [];
     for (const state of this.layers) {
       if (state.handler.legend) {
+        const hasData = hasLayerData(state.layer);
+        if (hasData) {
           legends.push(<div key={state.options.name}>{state.handler.legend}</div>);
         }
       }
+    }
 
     return legends;
   }

public/app/plugins/panel/geomap/utils/utils.test.ts

@@ -0,0 +1,120 @@
+import Feature from 'ol/Feature';
+import Point from 'ol/geom/Point';
+import LayerGroup from 'ol/layer/Group';
+import TileLayer from 'ol/layer/Tile';
+import VectorLayer from 'ol/layer/Vector';
+import WebGLPointsLayer from 'ol/layer/WebGLPoints';
+import TileSource from 'ol/source/Tile';
+import VectorSource from 'ol/source/Vector';
+
+// Mock the config module to avoid undefined panels error
+jest.mock('@grafana/runtime', () => ({
+  getTemplateSrv: jest.fn(),
+}));
+
+// Mock the dimensions module since it's imported by utils.ts
+jest.mock('app/features/dimensions', () => ({
+  getColorDimension: jest.fn(),
+  getScalarDimension: jest.fn(),
+  getScaledDimension: jest.fn(),
+  getTextDimension: jest.fn(),
+}));
+
+// Mock the grafana datasource since it's imported by utils.ts
+jest.mock('app/plugins/datasource/grafana/datasource', () => ({
+  getGrafanaDatasource: jest.fn(),
+}));
+
+import { hasLayerData } from './utils';
+
+// Test fixtures
+const createTestFeature = () => new Feature(new Point([0, 0]));
+
+const createTestVectorSource = (hasFeature = false): VectorSource<Point> => {
+  const source = new VectorSource<Point>();
+  if (hasFeature) {
+    source.addFeature(createTestFeature());
+  }
+  return source;
+};
+
+const createTestWebGLStyle = () => ({
+  symbol: {
+    symbolType: 'circle',
+    size: 8,
+    color: '#000000',
+    opacity: 1,
+  },
+});
+
+describe('hasLayerData', () => {
+  it('should return false for empty vector layer', () => {
+    const layer = new VectorLayer({
+      source: createTestVectorSource(),
+    });
+    expect(hasLayerData(layer)).toBe(false);
+  });
+
+  it('should return true for vector layer with features', () => {
+    const layer = new VectorLayer({
+      source: createTestVectorSource(true),
+    });
+    expect(hasLayerData(layer)).toBe(true);
+  });
+
+  it('should return true for layer group with data', () => {
+    const vectorLayer = new VectorLayer({
+      source: createTestVectorSource(true),
+    });
+    const group = new LayerGroup({
+      layers: [vectorLayer],
+    });
+    expect(hasLayerData(group)).toBe(true);
+  });
+
+  it('should return false for empty layer group', () => {
+    const group = new LayerGroup({
+      layers: [],
+    });
+    expect(hasLayerData(group)).toBe(false);
+  });
+
+  it('should return true for tile layer with source', () => {
+    const layer = new TileLayer({
+      source: new TileSource({}),
+    });
+    expect(hasLayerData(layer)).toBe(true);
+  });
+
+  it('should return false for tile layer without source', () => {
+    const layer = new TileLayer({});
+    expect(hasLayerData(layer)).toBe(false);
+  });
+
+  it('should return true for WebGLPointsLayer with features', () => {
+    const layer = new WebGLPointsLayer({
+      source: createTestVectorSource(true),
+      style: createTestWebGLStyle(),
+    });
+    expect(hasLayerData(layer)).toBe(true);
+  });
+
+  it('should return false for empty WebGLPointsLayer', () => {
+    const layer = new WebGLPointsLayer({
+      source: createTestVectorSource(),
+      style: createTestWebGLStyle(),
+    });
+    expect(hasLayerData(layer)).toBe(false);
+  });
+
+  it('should return true for layer group with WebGLPointsLayer containing data', () => {
+    const webglLayer = new WebGLPointsLayer({
+      source: createTestVectorSource(true),
+      style: createTestWebGLStyle(),
+    });
+    const group = new LayerGroup({
+      layers: [webglLayer],
+    });
+    expect(hasLayerData(group)).toBe(true);
+  });
+});

public/app/plugins/panel/geomap/utils/utils.ts

@@ -1,5 +1,17 @@
 import { Map as OpenLayersMap } from 'ol';
+import Geometry from 'ol/geom/Geometry';
+import Point from 'ol/geom/Point';
 import { defaults as interactionDefaults } from 'ol/interaction';
+import BaseLayer from 'ol/layer/Base';
+import LayerGroup from 'ol/layer/Group';
+import ImageLayer from 'ol/layer/Image';
+import TileLayer from 'ol/layer/Tile';
+import VectorLayer from 'ol/layer/Vector';
+import VectorImage from 'ol/layer/VectorImage';
+import WebGLPointsLayer from 'ol/layer/WebGLPoints';
+import ImageSource from 'ol/source/Image';
+import TileSource from 'ol/source/Tile';
+import VectorSource from 'ol/source/Vector';
 
 import { SelectableValue } from '@grafana/data';
 import { DataFrame, GrafanaTheme2 } from '@grafana/data/src';
@@ -144,3 +156,39 @@ export const isUrl = (url: string) => {
     return false;
   }
 };
+
+/**
+ * Checks if a layer has data to display
+ * @param layer The OpenLayers layer to check
+ * @returns boolean indicating if the layer has data
+ */
+export function hasLayerData(
+  layer:
+    | LayerGroup
+    | VectorLayer<VectorSource<Geometry>>
+    | VectorImage<VectorSource<Geometry>>
+    | WebGLPointsLayer<VectorSource<Point>>
+    | TileLayer<TileSource>
+    | ImageLayer<ImageSource>
+    | BaseLayer
+): boolean {
+  if (layer instanceof LayerGroup) {
+    return layer
+      .getLayers()
+      .getArray()
+      .some((subLayer) => hasLayerData(subLayer));
+  }
+  if (layer instanceof VectorLayer || layer instanceof VectorImage) {
+    const source = layer.getSource();
+    return source != null && source.getFeatures().length > 0;
+  }
+  if (layer instanceof WebGLPointsLayer) {
+    const source = layer.getSource();
+    return source != null && source.getFeatures().length > 0;
+  }
+  if (layer instanceof TileLayer || layer instanceof ImageLayer) {
+    // For tile/image layers, check if they have a source
+    return Boolean(layer.getSource());
+  }
+  return false;
+}