parse buffer to json

api/src/app.module.ts

@@ -6,6 +6,7 @@ import { AuthModule } from '@api/modules/auth/auth.module';
 import { NotificationsModule } from '@api/modules/notifications/notifications.module';
 import { EventsModule } from '@api/modules/events/events.module';
 import { AdminModule } from '@api/modules/admin/admin.module';
+import { ImportModule } from '@api/modules/import/import.module';
 
 @Module({
   imports: [
@@ -14,6 +15,7 @@ import { AdminModule } from '@api/modules/admin/admin.module';
     NotificationsModule,
     EventsModule,
     AdminModule,
+    ImportModule,
   ],
   controllers: [AppController],
   providers: [AppService],

api/src/modules/admin/admin.module.ts

@@ -1,10 +1,11 @@
 import { Module } from '@nestjs/common';
 import { AdminController } from './admin.controller';
 import { AuthModule } from '@api/modules/auth/auth.module';
-import { ImportController } from '@api/modules/import/import.controller';
+
+import { ImportModule } from '@api/modules/import/import.module';
 
 @Module({
-  imports: [AuthModule],
-  controllers: [AdminController, ImportController],
+  imports: [AuthModule, ImportModule],
+  controllers: [AdminController],
 })
 export class AdminModule {}

api/src/modules/import/import.controller.ts

@@ -10,18 +10,23 @@ import { RolesGuard } from '@api/modules/auth/guards/roles.guard';
 import { RequiredRoles } from '@api/modules/auth/decorators/roles.decorator';
 import { ROLES } from '@api/modules/auth/roles.enum';
 import { UploadXlsm } from '@api/modules/import/decorators/xlsm-upload.decorator';
+import {
+  ExcelParserInterface,
+  ExcelParserToken,
+} from '@api/modules/import/services/excel-parser.interface';
+import { XlsxParser } from '@api/modules/import/services/xlsx.parser';
 
 @Controller()
 //@UseInterceptors(JwtAuthGuard, RolesGuard)
 export class ImportController {
+  constructor(private readonly parser: XlsxParser) {}
   // TODO: File validation following:
   //       https://docs.nestjs.com/techniques/file-upload
 
   @Post('/admin/upload/xlsx')
   //@RequiredRoles(ROLES.ADMIN)
   @UseInterceptors(FileInterceptor('file'))
   async uploadFile(@UploadXlsm() file: Express.Multer.File): Promise<any> {
-    const { buffer, ...rest } = file;
-    return rest;
+    return this.parser.parseExcel(file.buffer);
   }
 }

api/src/modules/import/import.module.ts

@@ -1,9 +1,13 @@
 import { Module } from '@nestjs/common';
 import { ImportService } from './import.service';
-import { ImportController } from './import.controller';
+import { MulterModule } from '@nestjs/platform-express';
+import { ImportController } from '@api/modules/import/import.controller';
+
+import { XlsxParser } from '@api/modules/import/services/xlsx.parser';
 
 @Module({
-  providers: [ImportService],
-  controllers: [ImportController]
+  imports: [MulterModule.register({})],
+  controllers: [ImportController],
+  providers: [ImportService, XlsxParser],
 })
 export class ImportModule {}

api/src/modules/import/services/excel-parser.interface.ts

@@ -1,3 +1,5 @@
+export const ExcelParserToken = Symbol('ExcelParserInterface');
+
 export interface ExcelParserInterface {
-  parseExcel(file: Express.Multer.File): Promise<any>;
+  parseExcel(data: Buffer): Promise<any>;
 }

api/src/modules/import/services/xlsx.parser.ts

@@ -0,0 +1,18 @@
+import { ExcelParserInterface } from '@api/modules/import/services/excel-parser.interface';
+import { Injectable } from '@nestjs/common';
+import { read, utils, WorkBook, WorkSheet } from 'xlsx';
+
+@Injectable()
+export class XlsxParser implements ExcelParserInterface {
+  async parseExcel(buffer: Buffer): Promise<any> {
+    const workbook: WorkBook = read(buffer);
+    const sheet: WorkSheet = workbook.Sheets['master_table'];
+    const data: any[] = utils.sheet_to_json(sheet);
+    return data;
+  }
+
+  async sheetNames(file: Express.Multer.File): Promise<string[]> {
+    const workbook: WorkBook = read(file.buffer);
+    return workbook.SheetNames;
+  }
+}