how to make second stream work before first rxjs-CodePudding

this.productService.createProduct(form).subscribe((res) => {
  this.fileUploadService.remove(imageName).subscribe((res) => {
    this.closeDialog(true);
  })
})

I have this snipped from my code and how you can see, I'm subscribing to second request inside first one, I think this is a bad solution, do you know how to make the second stream work before first one, by using rxjs operators?

CodePudding user response：

If the this.fileUploadService.remove has to be executed before this.productService.createProduct then you can try

this.fileUploadService.remove(imageName).pipe(
  concatMap(() => this.productService.createProduct(form))
).subscribe(() => {
    this.closeDialog(true);
})

The key here is the use of concatMap which basically says "execute downstream after the upstream has notified some values".