Firestore: reference type.How wait for all get() call of evey result

Question

I am getting an Observable Ticket[]> from a firestore DB, one field in ticket is reference type.

When I subscribe for results I use:

 getTickets()
.subscribe(listOfTickets=> {  

     //loop the array
     listOfTickets.forEach(ticket => {

         ticket.personRef.get()  //this is the reference type field
         .then(res => { //getting information
            let person = res.data();
       }
     }         
     .... 
 }    

How can I wait for all the results in:

ticket.personRef.get()

I am trying using forkJoin, but I still do not understand how apply to this. The observable listOfTickets has a lot of results.

Answer 1

Do not use forEach. Use for

  async someFunction() {
    getTickets().subscribe(async listOfTickets => {
      const allTickets = [];
        for (let i = 0; i < listOfTickets.length; i++) {
          await listOfTickets [i].personRef.get().then(snapshot => {
            return snapshot.data();
          }).then(ticket => {
            allTickets.push(ticket);
          })
        }
      console.log(allTickets);
    })
  }