Property 'pipe' does not exist on type 'AngularFireObject<{}>'

Question

I\'m a beginner to Angular. I\'m watching the tutorial of Mosh Hamedani using the Angular version 6 but the problem is the tutorial version is 4. I\'m working on the e-comme

Answer 1

async  addToCart(product:Product){

  let cartId= await this.getOrCreateCart();
  let item$$=this.getItem(cartId,product.key);
  let item$=this.getItem(cartId,product.key).snapshotChanges();
    item$.pipe(take(1)).subscribe(item=>{
      this.data=item.payload.val();

        if(this.data!= null){
          item$$.update({product:product,quantity:(this.data.quantity)+1});
        }else{
          item$$.set({product:product,quantity:1});
        }


    });
  }