added Types for on(...).

src/plugins/expressions/common/expression_renderers/types.ts

@@ -80,3 +80,44 @@ export interface IInterpreterRenderHandlers {
    */
   uiState?: unknown;
 }
+
+type DefaultEmitters<T extends IInterpreterRenderHandlers> = Pick<T, 'done' | 'reload' | 'update'>;
+
+export class DefaultInterpreterRenderHandlers<Emitters = {}> implements IInterpreterRenderHandlers {
+  done() {}
+  onDestroy(fn: () => void) {}
+  reload() {}
+  update(params: any) {}
+  event(event: any) {}
+  getRenderMode() {
+    return 'noInteractivity' as RenderMode;
+  }
+  isSyncColorsEnabled() {
+    return false;
+  }
+  hasCompatibleActions?: (event: any) => Promise<boolean>;
+
+  on(event: keyof Emitters | keyof DefaultEmitters<this>, fn: (...args: any) => void) {
+    if (this[event as keyof this]) {
+      const eventCall = this[event as keyof this];
+      if (!eventCall || typeof eventCall !== 'function') return true;
+
+      const updatedEvent = (...args: unknown[]) => {
+        const preventFromCallingListener: void | boolean = eventCall(...args);
+        if (fn && typeof fn === 'function' && preventFromCallingListener === null) {
+          fn(...args);
+        }
+        return preventFromCallingListener;
+      };
+      this[event as keyof this] = (updatedEvent as unknown) as typeof eventCall;
+    }
+  }
+
+  uiState?: unknown;
+}
+
+export type InterpreterRenderHandlers<T = {}> = T & DefaultInterpreterRenderHandlers<T>;
+
+export function getDefaultHandlers<T = {}>(): InterpreterRenderHandlers<T> {
+  return new DefaultInterpreterRenderHandlers<T>() as InterpreterRenderHandlers<T>;
+}

src/plugins/expressions/public/render.ts

@@ -11,7 +11,12 @@ import { Observable } from 'rxjs';
 import { filter } from 'rxjs/operators';
 import { ExpressionRenderError, RenderErrorHandlerFnType, IExpressionLoaderParams } from './types';
 import { renderErrorHandler as defaultRenderErrorHandler } from './render_error_handler';
-import { IInterpreterRenderHandlers, ExpressionAstExpression, RenderMode } from '../common';
+import {
+  ExpressionAstExpression,
+  RenderMode,
+  getDefaultHandlers,
+  InterpreterRenderHandlers,
+} from '../common';
 
 import { getRenderersRegistry } from './services';
 
@@ -45,7 +50,7 @@ export class ExpressionRenderHandler {
   private renderSubject: Rx.BehaviorSubject<number | null>;
   private eventsSubject: Rx.Subject<unknown>;
   private updateSubject: Rx.Subject<UpdateValue | null>;
-  private handlers: IInterpreterRenderHandlers;
+  private handlers: InterpreterRenderHandlers;
   private onRenderError: RenderErrorHandlerFnType;
 
   constructor(
@@ -71,8 +76,9 @@ export class ExpressionRenderHandler {
 
     this.updateSubject = new Rx.Subject();
     this.update$ = this.updateSubject.asObservable();
-
+    this.handlers = getDefaultHandlers();
     this.handlers = {
+      on: this.handlers.on,
       onDestroy: (fn: any) => {
         this.destroyFn = fn;
       },
@@ -89,6 +95,7 @@ export class ExpressionRenderHandler {
       event: (data) => {
         this.eventsSubject.next(data);
       },
+
       getRenderMode: () => {
         return renderMode || 'display';
       },
@@ -126,7 +133,7 @@ export class ExpressionRenderHandler {
           ...this.handlers,
           uiState,
         } as any);
-    } catch (e) {
+    } catch (e: any) {
       return this.handleRenderError(e);
     }
   };