title: Get Firestore subcollections
body: <p>I have a problem with getting data from the <strong>Firestore</strong> with a following structure:</p>
  
  <p><a href="https://i.stack.imgur.com/g2tsI.png" rel="noreferrer"><img src="https://i.stack.imgur.com/g2tsI.png" alt="Firestore structure"></a></p>
  
  <p>Here is how I get category collection:</p>
  
  <pre><code>var defaultStore: Firestore?
  var location: [DocumentSnapshot] = []
  
  override func viewDidLoad() {
      super.viewDidLoad()
      defaultStore = Firestore.firestore()
  
      defaultStore?.collection("Category").getDocuments { (querySnapshot: QuerySnapshot?, error: Error?) in
          if let error = error {
              print(error.localizedDescription)
          } else {
              self.location = (querySnapshot?.documents)!
              DispatchQueue.main.async {
                  self.tableView.reloadData()
              }
          }
      }
  }
  </code></pre>
  
  <p>It gives me: <code>Books</code>, <code>Films</code>, <code>From test</code> and <code>Serials</code>.
  But how can I get collections from <code>Films</code> for example?</p>