How can I add a search users function? - ios

Question

I've been trying to add a search users mechanism for quite a while now, but to no success. I can't seem to find much out there, and where there is explanation it is almost always for FirebaseDatabase rather than Firestore. I'm very new to Swift, Firebase and coding in general so any explanation about where I'm going wrong with this, and how I can implement this would be appreciated beyond words.
This is my latest attempt (I'm sure this will make many of you shudder):
import UIKit
import Firebase
import FirebaseAuth
import FirebaseFirestore
class FindUsersViewController: UITableViewController {
var usersArray = [String]()
var filteredUsers = [String]()
override func viewDidLoad() {
super.viewDidLoad()
fetchUser()
// Do any additional setup after loading the view.
}
func fetchUser() {
let db = Firestore.firestore()
let usernameSearch = db.collection("users")
usernameSearch.getDocuments { (snapshot, error) in
if error != nil {
print("Error obtaining usernames")
} else {
for document in snapshot!.documents {
let field = document.data()["username"]
self.usersArray.append(field as! String)
print(self.usersArray)
}
}
}
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 5
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: .subtitle, reuseIdentifier: "Cell")
cell.textLabel?.text = usersArray
return cell
}
}
I can't quite seem to work it out, and because I'm new to everything, the Firebase Documentation seems more mystifying than enlightening, so any help with this would be greatly appreciated!
(I think I'm going wrong with Arrays...maybe...idk...)
--
I should add:
I have a collection of "users", with documents for each user containing the "username" field (along with uid, password and email fields).

Answer 1

You're almost there!
First let's create a User object that will represent all the properties for your user. For now let's say a user has an id, an name and an email, but feel free to match your project requirements:
import FirebaseFirestore
struct User {
let id: String
let name: String
let email: String
}
We also add an extension with a convenience initializer for our User, this will allow us to convert quickly and easily a Firestore Document to a User:
extension User {
init(queryDocument: QueryDocumentSnapshot) {
guard let name = queryDocument.data()["name"] as? String else { fatalError() }
guard let email = queryDocument.data()["email"] as? String else { fatalError() }
self.init(id: queryDocument.documentID, name: name, email: email)
}
}
Now, this is how your FindUsersViewController could look like:
import UIKit
import FirebaseFirestore
class FindUsersViewController: UITableViewController {
// Keep a reference to your database, and your users collection:
private let database = Firestore.firestore()
private lazy var usersReference = database.collection("users")
private let cellReuseIdentifier = "cellReuseIdentifier"
// This is the array that will keep track of your users, you will use it to populate your table view data:
private var users = [User]()
override func viewDidLoad() {
super.viewDidLoad()
// Set your table view datasource and delegate:
tableView.dataSource = self
tableView.delegate = self
// Register your cell identifier:
tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellReuseIdentifier)
fetchUsers()
}
private func fetchUsers() {
// Create your query, for instance we will return only the first 10 users and ordered by name:
let query = usersReference.order(by: "name", descending: true).limit(to: 10)
// Now simply fetch the documents that match the query:
query.getDocuments { [weak self] (querySnapshot, error) in
guard let self = self else { return }
guard let querySnapshot = querySnapshot, error == nil else {
// Oops, something wrong happened here
return
}
// You get successfully your documents here, so just transform them to your User model:
let users = querySnapshot.documents.map { User(queryDocument: $0) }
// Then fill your array, and make sure you reload your table data on the main thread:
DispatchQueue.main.async {
self.users = users
self.tableView.reloadData()
}
}
}
// MARK: UITableViewDataSource methods
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Returns the number of users in your array:
return users.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseIdentifier, for: indexPath)
// Configure your cell here via your users array:
cell.textLabel?.text = users[indexPath.row].name
return cell
}
// MARK: UITableViewDelegate methods
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension
}
}
This will give you a nice list of your users. I added a lot of comments in the view controller so I think it's pretty self-explanatory, but feel free to let me know if you still have a doubt.
Good luck with your app! :)