Incorporating Angluar's HttpClient and a Service is essential for efficient implementation in Angular.
To utilize HttpClient effectively, we must first include the HttpClientModule within the relevant Module of our project.
@NgModule({
imports: [HttpClientModule],
...
})
export class AppModule {}
Subsequently, establishing a generic Image Service that accesses HttpClient through dependency injection is crucial.
@Injectable()
export class ImageService {
constructor(private http: HttpClient) { }
}
Once these steps are completed, we can proceed to create the function in our service:
imageUrlToBase64(url: string) {
return this.http.get(url, {
observe: 'body',
responseType: 'arraybuffer',
})
.pipe(
take(1),
map((arrayBuffer) =>
btoa(
Array.from(new Uint8Array(arrayBuffer))
.map((b) => String.fromCharCode(b))
.join('')
)
),
)
}
By using http.get with an arraybuffer response type, we receive the image data as an ArrayBuffer, enabling us to convert it into a base64 string easily. Alternative methods can be explored on this helpful SO Question.
// code snippet from above
map(
btoa(
Array.from(new Uint8Array(arrayBuffer))
.map((b) => String.fromCharCode(b))
.join('')
)
)
With the function now implemented, we can move on to utilization:
@Component()
export class AppComponent {
base64Image: string;
constructor(private imageService: ImageService) {
this.imageService.imageUrlToBase64('https://picsum.photos/200/300').subscribe(
base64 => {
this.base64Image = base64
})
}
}
At this stage, the image is accessible in base64 format.