根据对象值对可观察对象数组进行排序

Question

I am returning an array of Observables from firestore, and want to order them by the index I created within the object in the database.

They are stored in the database like so:

They then display in the UI in the order based on the key ID (Alphabetically), however, I want them ordered in the UI based on the index. I do, however, need to keep the id as the initial key.

I have tried mapping the values and using sort() to to order by index shown in the ode below, but still returns in random order.

This is how I have used map to try and order by the key value of index.

this.bedrooms$ = this.property$.pipe(
     flatMap((property: any) => this._property.getAllBedrooms(property.bedrooms, this.propertyId))
   );


   this.sortedBedroom$ = this.bedrooms$.pipe(
     map((room: any) => {
      return room.sort((a: any, b: any) =>
          b.index - a.index
       );
     }
     )
   );

Answer 1

Your issue is maybe related to this line b.test - a.index instead of b.index - a.index .

I would suggest another solution for this, getting data sorted from the firestore using AngularFirestore from @angular/fire :

this.afs.collection<Bedroom>('bedrooms', ref => ref.orderBy('index'))