[Maps] data load event handlers (#49373)

* [Maps] data load event handlers

* update readme featuresCount to reflect variable name

* fix exception with EMS_TMS onDataLoadEnd

* wrap featuresCount in resultMeta object so different layer types can return different results

x-pack/legacy/plugins/maps/public/actions/map_actions.js

@@ -21,10 +21,15 @@ import { FLYOUT_STATE } from '../reducers/ui';
 import {
   cancelRequest,
   registerCancelCallback,
-  unregisterCancelCallback
+  unregisterCancelCallback,
+  getEventHandlers,
 } from '../reducers/non_serializable_instances';
 import { updateFlyout } from '../actions/ui_actions';
-import { FEATURE_ID_PROPERTY_NAME, SOURCE_DATA_ID_ORIGIN } from '../../common/constants';
+import {
+  FEATURE_ID_PROPERTY_NAME,
+  LAYER_TYPE,
+  SOURCE_DATA_ID_ORIGIN
+} from '../../common/constants';
 
 export const SET_SELECTED_LAYER = 'SET_SELECTED_LAYER';
 export const SET_TRANSIENT_LAYER = 'SET_TRANSIENT_LAYER';
@@ -456,6 +461,14 @@ export function startDataLoad(layerId, dataId, requestToken, meta = {}) {
       dispatch(cancelRequest(layer.getPrevRequestToken(dataId)));
     }
 
+    const eventHandlers = getEventHandlers(getState());
+    if (eventHandlers && eventHandlers.onDataLoad) {
+      eventHandlers.onDataLoad({
+        layerId,
+        dataId,
+      });
+    }
+
     dispatch({
       meta,
       type: LAYER_DATA_LOAD_STARTED,
@@ -480,9 +493,26 @@ export function updateSourceDataRequest(layerId, newData) {
 }
 
 export function endDataLoad(layerId, dataId, requestToken, data, meta) {
-  return async (dispatch) => {
+  return async (dispatch, getState) => {
     dispatch(unregisterCancelCallback(requestToken));
-    const features = data ? data.features : [];
+
+    const features = data && data.features ? data.features : [];
+
+    const eventHandlers = getEventHandlers(getState());
+    if (eventHandlers && eventHandlers.onDataLoadEnd) {
+      const layer = getLayerById(layerId, getState());
+      const resultMeta = {};
+      if (layer && layer.getType() === LAYER_TYPE.VECTOR) {
+        resultMeta.featuresCount = features.length;
+      }
+
+      eventHandlers.onDataLoadEnd({
+        layerId,
+        dataId,
+        resultMeta
+      });
+    }
+
     dispatch(cleanTooltipStateForLayer(layerId, features));
     dispatch({
       type: LAYER_DATA_LOAD_ENDED,
@@ -503,8 +533,18 @@ export function endDataLoad(layerId, dataId, requestToken, data, meta) {
 }
 
 export function onDataLoadError(layerId, dataId, requestToken, errorMessage) {
-  return async (dispatch) => {
+  return async (dispatch, getState) => {
     dispatch(unregisterCancelCallback(requestToken));
+
+    const eventHandlers = getEventHandlers(getState());
+    if (eventHandlers && eventHandlers.onDataLoadError) {
+      eventHandlers.onDataLoadError({
+        layerId,
+        dataId,
+        errorMessage,
+      });
+    }
+
     dispatch(cleanTooltipStateForLayer(layerId));
     dispatch({
       type: LAYER_DATA_LOAD_ERROR,

x-pack/legacy/plugins/maps/public/embeddable/README.md

@@ -58,3 +58,21 @@ const renderTooltipContent = ({ addFilters, closeTooltip, features, isLocked, lo
 
 const mapEmbeddable = await factory.createFromState(state, input, parent, renderTooltipContent);
 ```
+
+
+#### Event handlers
+```
+const eventHandlers = {
+  onDataLoad: (layerId: string, dataId: string) => {
+    // take action on data load
+  },
+  onDataLoadEnd: (layerId: string, dataId: string, resultMeta: object) => {
+    // take action on data load end
+  },
+  onDataLoadError: (layerId: string, dataId: string, errorMessage: string) => {
+    // take action on data load error
+  },
+}
+
+const mapEmbeddable = await factory.createFromState(state, input, parent, renderTooltipContent, eventHandlers);
+```

x-pack/legacy/plugins/maps/public/embeddable/map_embeddable.js

@@ -31,14 +31,14 @@ import {
   setOpenTOCDetails,
 } from '../actions/ui_actions';
 import { getIsLayerTOCOpen, getOpenTOCDetails } from '../selectors/ui_selectors';
-import { getInspectorAdapters } from '../reducers/non_serializable_instances';
+import { getInspectorAdapters, setEventHandlers } from '../reducers/non_serializable_instances';
 import { getMapCenter, getMapZoom } from '../selectors/map_selectors';
 import { MAP_SAVED_OBJECT_TYPE } from '../../common/constants';
 
 export class MapEmbeddable extends Embeddable {
   type = MAP_SAVED_OBJECT_TYPE;
 
-  constructor(config, initialInput, parent, renderTooltipContent) {
+  constructor(config, initialInput, parent, renderTooltipContent, eventHandlers) {
     super(
       initialInput,
       {
@@ -50,6 +50,7 @@ export class MapEmbeddable extends Embeddable {
       parent);
 
     this._renderTooltipContent = renderTooltipContent;
+    this._eventHandlers = eventHandlers;
     this._layerList = config.layerList;
     this._store = createMapStore();
 
@@ -98,6 +99,7 @@ export class MapEmbeddable extends Embeddable {
    * @param {ContainerState} containerState
    */
   render(domNode) {
+    this._store.dispatch(setEventHandlers(this._eventHandlers));
     this._store.dispatch(setReadOnly(true));
     this._store.dispatch(disableScrollZoom());
 

x-pack/legacy/plugins/maps/public/embeddable/map_embeddable_factory.js

@@ -123,6 +123,7 @@ export class MapEmbeddableFactory extends EmbeddableFactory {
     input,
     parent,
     renderTooltipContent,
+    eventHandlers,
   ) {
     const layerList = state && state.layerList ? state.layerList : getInitialLayers();
     const indexPatterns = await this._getIndexPatterns(layerList);
@@ -137,7 +138,8 @@ export class MapEmbeddableFactory extends EmbeddableFactory {
       },
       input,
       parent,
-      renderTooltipContent
+      renderTooltipContent,
+      eventHandlers,
     );
   }
 

x-pack/legacy/plugins/maps/public/layers/layer.js

@@ -406,5 +406,9 @@ export class AbstractLayer {
     mbMap.setLayoutProperty(mbLayerId, 'visibility', this.isVisible() ? 'visible' : 'none');
   }
 
+  getType() {
+    return this._descriptor.type;
+  }
+
 }
 

x-pack/legacy/plugins/maps/public/reducers/non_serializable_instances.js

@@ -10,6 +10,7 @@ import { MapAdapter } from '../inspector/adapters/map_adapter';
 
 const REGISTER_CANCEL_CALLBACK = 'REGISTER_CANCEL_CALLBACK';
 const UNREGISTER_CANCEL_CALLBACK = 'UNREGISTER_CANCEL_CALLBACK';
+const SET_EVENT_HANDLERS = 'SET_EVENT_HANDLERS';
 
 function createInspectorAdapters() {
   const inspectorAdapters = {
@@ -27,6 +28,7 @@ export function nonSerializableInstances(state, action = {}) {
     return {
       inspectorAdapters: createInspectorAdapters(),
       cancelRequestCallbacks: new Map(), // key is request token, value is cancel callback
+      eventHandlers: {},
     };
   }
 
@@ -41,6 +43,12 @@ export function nonSerializableInstances(state, action = {}) {
       return {
         ...state,
       };
+    case SET_EVENT_HANDLERS: {
+      return {
+        ...state,
+        eventHandlers: action.eventHandlers
+      };
+    }
     default:
       return state;
 
@@ -57,6 +65,10 @@ export const getCancelRequestCallbacks = ({ nonSerializableInstances }) => {
   return nonSerializableInstances.cancelRequestCallbacks;
 };
 
+export const getEventHandlers = ({ nonSerializableInstances }) => {
+  return nonSerializableInstances.eventHandlers;
+};
+
 // Actions
 export const registerCancelCallback = (requestToken, callback) => {
   return {
@@ -86,3 +98,10 @@ export const cancelRequest = (requestToken) => {
     }
   };
 };
+
+export const setEventHandlers = (eventHandlers = {}) => {
+  return {
+    type: SET_EVENT_HANDLERS,
+    eventHandlers,
+  };
+};