Access specific item within a Firebase Collection using angular

Question

I’m with an angular project and I’m using firebase cloud firestore as a database but I’m having a hard time using it because I have a collection called feed and within this collection I have several items and I need to pick only one item using its key however all the methods I tried didn’t work.

my service:

import { Injectable } from '@angular/core';
import { AngularFirestore } from '@angular/fire/firestore';


@Injectable()

export class TestService {
  constructor(private firestore: AngularFirestore) { }
  /* create_NewIcecream : Cria um novo registro na coleção especificada usando o método add */
  criar_novo_user(record) {
    return this.firestore.collection('user').add(record);
  }
  /*read_Icecream: Chama o método snapshotChanges , que obterá registros e também será registrado para receber atualizações */
  read_userPrincipal(){
    return this.firestore.collection('user').snapshotChanges();
  }
  read_feddUser(key:string){
    return this.firestore.collection('feed').get;
  }
  update_like(recordID,record) {
   return this.firestore.doc('feed/' + recordID).update(record);
  }
  carregar_publicacao(){
    return this.firestore.collection('feed').snapshotChanges();
  }

}

my component

import { Component, OnInit, Input } from '@angular/core';
import { Publicacao } from './publi.model';
import { TestService } from 'src/app/test.service';


@Component({
  selector: 'app-publi',
  templateUrl: './publi.component.html',
  styleUrls: ['./publi.component.css']
})
export class PubliComponent implements OnInit {

  @Input() publicacao: Publicacao

  constructor(private testeService: TestService) { }


  ngOnInit(){}

  like(item){
    let arrey;
    arrey = this.testeService.read_feddUser(item.token)
    console.log(arrey)
  }
}

in that like function is where I need to read only the item with its key.

Answer 1

It is possible to check some problems in the method read_feddUser.

get is a method. Therefore, it is necessary to change to get().

Although receive a parameter (key:string), it is not used. In this case you would not be able to return an item by its ID. It is necessary to change to

this.firestore.collection('feed').doc(key).get();

You return the get() from the firestore to your component and get() returns a promisse. So you need to change your component to read promisse. Something like this:

like(item) {
  let feed;
  this.testeService.read_feddUser(item.token)
  .then(function(doc) {
    feed = doc;
    console.log(feed);
  }