Need acces from document to collection Firestore - swift

Question

I'm trying to do an iOS app and i've binded it with firebase, so I'm trying to get some posts ad fetch them, and this works fine, however this posts got 2 collections (likes and replies) and i'm trying to fetch likes, the thing is that I can't get the likes because for some reasons I can't a class for document forEach neither I can't access it, someone got any idea?
Code:
import Foundation
import Firebase
struct Post : Hashable {
var id : String
var dateAdded : String
var posterEmail : String
var posterUsername : String
var posterIcon : String
var postTitle : String
var postBody : String
var likes : [String]
var userLikedPost : Bool
}
struct Like {
var likeId : String
var likerEmail : String
}
class Likes {
var likes : [Like] = []
func fetchLikes() {
//Firestore.firestore()
}
}
class Posts : ObservableObject {
#Published var posts : [Post] = []
func fetchPosts() {
Firestore.firestore().collection("posts").getDocuments(completion: { (docPosts, error) in
if (error != nil) {
print("error fetching posts")
} else {
docPosts?.documents.forEach { (post) in
let id = post.documentID
let email = post.get("posterEmail") as! String
let username = post.get("posterUsername") as! String
let icon = post.get("posterIcon") as! String
let title = post.get("title") as! String
let body = post.get("body") as! String
// Here i want to insert the code that gets the likes class and access the likes variable
self.posts.append(Post(id: id, dateAdded:String(id.split(separator: "_").joined(separator: "/").prefix(10)) ,posterEmail: email, posterUsername: username, posterIcon: icon, postTitle: title, postBody: body,
likes: [],userLikedPost: false))
}
}
})
}
}

Answer 1

The Firestore structure was not included in the question so I will present one for use
user_wines
uid_0
name: "Jay"
favorite_wines:
0: "Insignia"
1: "Scavino Bricco Barolo"
2: "Lynch Bages"
uid_1
name: "Cindy"
favorite_wines
0: "Palermo"
1: "Mercury Head"
2: "Scarecrow"
And then the code to read all of the user documents, get the name, the wine list (as an array as Strings) and output it to console
func readArrayOfStrings() {
let usersCollection = self.db.collection("user_wines")
usersCollection.getDocuments(completion: { snapshot, error in
guard let allDocs = snapshot?.documents else { return }
for doc in allDocs {
let name = doc.get("name") as? String ?? "No Name"
let wines = doc.get("favorite_wines") as? [String] ?? []
wines.forEach { print(" ", $0) }
}
})
}
and the output
Jay
Insignia
Scavino Bricco Barolo
Lynch Bages
Cindy
Palermo
Mercury Head
Scarecrow
EDIT
Here's the same code using Codable
class UserWineClass: Codable {
#DocumentID var id: String?
var name: String
var favorite_wines: [String]
}
and the code to read data into the class
for doc in allDocs {
do {
let userWine = try doc.data(as: UserWineClass.self)
print(userWine.name)
userWine.favorite_wines.forEach { print(" ", $0) }
} catch {
print(error)
}
}