To upload the image to our server, we are using postFile() on VisionAPIService. Let's create this service now. Inside the clientappservices folder, create a file named vision.api.service.ts and update it as follows:

// SNIPP SNIPP
import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';

@Injectable()
export class VisionAPIService {

         constructor(private http: HttpClient) {}

         postFile(threadId: string, fileToUpload: File): Observable < any > {
             const formData: FormData = new FormData();
             formData.append('image-reply', fileToUpload, fileToUpload.name);
             return this.http.post < any > (`/api/upload-image/${threadId}`, formData);
         }
}
// SNIPP SNIPP

We need to add this service as a provider in clientappapp.module.ts. First, we will import VisionAPIService into clientappapp.module.ts:

// SNIPP SNIPP
import { VisionAPIService } from './services/vision.api.service';
// SNIPP SNIPP

Update the providers as follows:

// SNIPP SNIPP
providers: [
    AuthService,
    AuthGuardLogin,
    AuthGuardAdmin,
    UserService,
    ThreadService,
    MessageService,
    VisionAPIService,
    {
        provide: HTTP_INTERCEPTORS,
        useClass: TokenInterceptor,
        multi: true
    }
],
// SNIPP SNIPP

Save all the files to continue.