RocketChat · d-gubert · Dec 16, 2021 · Dec 9, 2021
diff --git a/src/definition/email/IEmailDescriptor.ts b/src/definition/email/IEmailDescriptor.ts
@@ -0,0 +1,12 @@
+
+export interface IEmailDescriptor {
+    from?: string | undefined;
+    to?: string | Array<string> | undefined;
+    cc?: string | Array<string> | undefined;
+    bcc?: string | Array<string> | undefined;
+    replyTo?: string | Array<string> | undefined;
+    subject?: string | undefined;
+    text?: string | undefined;
+    html?: string | undefined;
+    headers?: Record<string, string> | undefined;
+}
diff --git a/src/definition/email/IPreEmailSent.ts b/src/definition/email/IPreEmailSent.ts
@@ -0,0 +1,25 @@
+import { IEmailDescriptor, IPreEmailSentContext } from '.';
+import { IHttp, IModify, IPersistence, IRead } from '../accessors';
+import { AppMethod } from '../metadata';
+
+/**
+ * Event interface that allows apps to
+ * register as a handler of of the `IPreEmailSent`
+ * event.
+ *
+ * This event is trigger before the mailer sends
+ * an email.
+ *
+ * To prevent the email from being sent, you can
+ * throw an error with a message specifying the
+ * reason for rejection.
+ */
+export interface IPreEmailSent {
+    [AppMethod.EXECUTE_PRE_EMAIL_SENT](
+        context: IPreEmailSentContext,
+        read: IRead,
+        http: IHttp,
+        persis: IPersistence,
+        modify: IModify,
+    ): Promise<IEmailDescriptor>;
+}
diff --git a/src/definition/email/IPreEmailSentContext.ts b/src/definition/email/IPreEmailSentContext.ts
@@ -0,0 +1,6 @@
+import { IEmailDescriptor } from './IEmailDescriptor';
+
+export interface IPreEmailSentContext {
+    context: unknown;
+    email: IEmailDescriptor;
+}
diff --git a/src/definition/email/index.ts b/src/definition/email/index.ts
@@ -0,0 +1,2 @@
+export * from './IEmailDescriptor';
+export * from './IPreEmailSentContext';
diff --git a/src/definition/metadata/AppInterface.ts b/src/definition/metadata/AppInterface.ts
@@ -41,4 +41,6 @@ export enum AppInterface {
     IPostLivechatRoomSaved = 'IPostLivechatRoomSaved',
     // FileUpload
     IPreFileUpload = 'IPreFileUpload',
+    // Email
+    IPreEmailSent = 'IPreEmailSent',
 }
diff --git a/src/definition/metadata/AppMethod.ts b/src/definition/metadata/AppMethod.ts
@@ -73,4 +73,6 @@ export enum AppMethod {
     EXECUTE_POST_LIVECHAT_ROOM_SAVED = 'executePostLivechatRoomSaved',
     // FileUpload
     EXECUTE_PRE_FILE_UPLOAD = 'executePreFileUpload',
+    // Email
+    EXECUTE_PRE_EMAIL_SENT = 'executePreEmailSent',
 }
diff --git a/src/server/managers/AppListenerManager.ts b/src/server/managers/AppListenerManager.ts
@@ -1,3 +1,4 @@
+import { IEmailDescriptor, IPreEmailSentContext } from '../../definition/email';
 import { EssentialAppDisabledException } from '../../definition/exceptions';
 import { IExternalComponent } from '../../definition/externalComponent';
 import { ILivechatEventContext, ILivechatRoom, ILivechatTransferEventContext, IVisitor } from '../../definition/livechat';
@@ -33,7 +34,8 @@ type EventData = (
     IRoomUserJoinedContext |
     IRoomUserLeaveContext |
     ILivechatTransferEventContext |
-    IFileUploadContext
+    IFileUploadContext |
+    IPreEmailSentContext
 );
 
 type EventReturn = (
@@ -43,7 +45,8 @@ type EventReturn = (
     IRoom |
     IUser |
     IUIKitResponse |
-    ILivechatRoom
+    ILivechatRoom |
+    IEmailDescriptor
 );
 
 export class AppListenerManager {
@@ -224,6 +227,9 @@ export class AppListenerManager {
             // FileUpload
             case AppInterface.IPreFileUpload:
                 return this.executePreFileUpload(data as IFileUploadContext);
+            // Email
+            case AppInterface.IPreEmailSent:
+                return this.executePreEmailSent(data as IPreEmailSentContext);
             default:
                 console.warn('An invalid listener was called');
                 return;
@@ -1147,4 +1153,27 @@ export class AppListenerManager {
             }
         }
     }
+
+    private async executePreEmailSent(data: IPreEmailSentContext): Promise<IEmailDescriptor> {
+        let descriptor = data.email;
+
+        for (const appId of this.listeners.get(AppInterface.IPreEmailSent)) {
+            const app = this.manager.getOneById(appId);
+
+            if (app.hasMethod(AppMethod.EXECUTE_PRE_EMAIL_SENT)) {
+                descriptor = await app.call(AppMethod.EXECUTE_PRE_EMAIL_SENT,
+                    {
+                        context: data.context,
+                        email: descriptor,
+                    },
+                    this.am.getReader(appId),
+                    this.am.getHttp(appId),
+                    this.am.getPersistence(appId),
+                    this.am.getModifier(appId),
+                );
+            }
+        }
+
+        return descriptor;
+    }
 }
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		export * from './IEmailDescriptor';
		export * from './IPreEmailSentContext';