feat: use event emitter for webhook(WIP)

Signed-off-by: Pranav C <pranavxc@gmail.com>

packages/nocodb/src/Noco.ts

@@ -9,6 +9,7 @@ import { NC_LICENSE_KEY } from './constants';
 import Store from './models/Store';
 import type { Express } from 'express';
 import type * as http from 'http';
+import { IEventEmitter } from './modules/event-emitter/event-emitter.interface'
 
 export default class Noco {
   private static _this: Noco;
@@ -30,6 +31,7 @@ export default class Noco {
   }
 
   public static config: any;
+  public static eventEmitter: IEventEmitter;
   public readonly router: express.Router;
   public readonly projectRouter: express.Router;
   public static _ncMeta: any;

packages/nocodb/src/app.module.ts

@@ -1,4 +1,4 @@
-import { Module, RequestMethod } from '@nestjs/common';
+import { Inject, Module, RequestMethod } from '@nestjs/common'
 import { APP_FILTER } from '@nestjs/core';
 import { Connection } from './connection/connection';
 import { GlobalExceptionFilter } from './filters/global-exception/global-exception.filter';
@@ -7,6 +7,7 @@ import { GlobalMiddleware } from './middlewares/global/global.middleware';
 import { GuiMiddleware } from './middlewares/gui/gui.middleware';
 import { PublicMiddleware } from './middlewares/public/public.middleware';
 import { DatasModule } from './modules/datas/datas.module';
+import { IEventEmitter } from './modules/event-emitter/event-emitter.interface'
 import { AuthService } from './services/auth.service';
 import { UsersModule } from './modules/users/users.module';
 import { MetaService } from './meta/meta.service';
@@ -51,6 +52,7 @@ export class AppModule implements OnApplicationBootstrap {
   constructor(
     private readonly connection: Connection,
     private readonly metaService: MetaService,
+    @Inject('IEventEmitter') private readonly eventEmitter: IEventEmitter,
   ) {}
 
   // Global Middleware
@@ -80,6 +82,7 @@ export class AppModule implements OnApplicationBootstrap {
     // temporary hack
     Noco._ncMeta = this.metaService;
     Noco.config = this.connection.config;
+    Noco.eventEmitter = this.eventEmitter;
 
     // init plugin manager
     await NcPluginMgrv2.init(Noco.ncMeta);

packages/nocodb/src/modules/event-emitter/event-emitter.interface.ts

@@ -0,0 +1,6 @@
+export interface IEventEmitter {
+  emit(event: string, arg: any): void;
+  on(event: string, listener: (arg: any) => void): () => void;
+  removeListener(event: string, listener: (arg: any) => void): void;
+  removeAllListeners(event?: string): void;
+}

packages/nocodb/src/modules/event-emitter/event-emitter.module.ts

@@ -0,0 +1,16 @@
+import { Global, Module } from '@nestjs/common';
+import { FallbackEventEmitter } from './fallback-event-emitter';
+
+@Global()
+@Module({
+  providers: [
+    {
+      provide: 'IEventEmitter',
+      useFactory: () => {
+        return new FallbackEventEmitter();
+      },
+    },
+  ],
+  exports: ['IEventEmitter'],
+})
+export class EventEmitterModule {}

packages/nocodb/src/modules/event-emitter/fallback-event-emitter.ts

@@ -0,0 +1,27 @@
+import Emittery from 'emittery';
+import { IEventEmitter } from './event-emitter.interface';
+
+export class FallbackEventEmitter implements IEventEmitter {
+  private readonly emitter: Emittery;
+
+  constructor() {
+    this.emitter = new Emittery();
+  }
+
+  emit(event: string, data: any): void {
+    this.emitter.emit(event, data);
+  }
+
+  on(event: string, listener: (...args: any[]) => void) {
+    this.emitter.on(event, listener);
+    return () => this.emitter.off(event, listener);
+  }
+
+  removeListener(event: string, listener: (...args: any[]) => void): void {
+    this.emitter.off(event, listener);
+  }
+
+  removeAllListeners(event?: string): void {
+    this.emitter.clearListeners(event);
+  }
+}

packages/nocodb/src/modules/event-emitter/nestjs-event-emitter.ts

@@ -0,0 +1,23 @@
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { IEventEmitter } from './event-emitter.interface';
+
+export class NestjsEventEmitter implements IEventEmitter {
+  constructor(private readonly eventEmitter: EventEmitter2) {}
+
+  emit(event: string, data: any): void {
+    this.eventEmitter.emit(event, data);
+  }
+
+  on(event: string, listener: (...args: any[]) => void) {
+    this.eventEmitter.on(event, listener);
+    return () => this.eventEmitter.removeListener(event, listener);
+  }
+
+  removeListener(event: string, listener: (...args: any[]) => void): void {
+    this.eventEmitter.removeListener(event, listener);
+  }
+
+  removeAllListeners(event?: string): void {
+    this.eventEmitter.removeAllListeners(event);
+  }
+}