Build a User Management App with Swift and SwiftUI

This tutorial demonstrates how to build a basic user management app. The app authenticates and identifies the user, stores their profile information in the database, and allows the user to log in, update their profile details, and upload a profile photo. The app uses:

Supabase Database - a Postgres database for storing your user data and Row Level Security so data is protected and users can only access their own information.
Supabase Auth - users log in through magic links sent to their email (without having to set up passwords).
Supabase Storage - users can upload a profile photo.

Supabase User Management example

If you get stuck while working through this guide, refer to the full example on GitHub.

Project setup#

Before we start building we're going to set up our Database and API. This is as simple as starting a new Project in Supabase and then creating a "schema" inside the database.

Create a project#

Create a new project in the Supabase Dashboard.
Enter your project details.
Wait for the new database to launch.

Set up the database schema#

Now we are going to set up the database schema. We can use the "User Management Starter" quickstart in the SQL Editor, or you can just copy/paste the SQL from below and run it yourself.

Go to the SQL Editor page in the Dashboard.
Click User Management Starter.
Click Run.

You can easily pull the database schema down to your local project by running the db pull command. Read the local development docs for detailed instructions.

supabase link --project-ref <project-id>
# You can get <project-id> from your project's dashboard URL: https://supabase.com/dashboard/project/<project-id>
supabase db pull

Get the API Keys#

Now that you've created some database tables, you are ready to insert data using the auto-generated API. We just need to get the Project URL and anon key from the API settings.

Go to the API Settings page in the Dashboard.
Find your Project URL, anon, and service_role keys on this page.

Building the App#

Let's start building the SwiftUI app from scratch.

Create a SwiftUI app in Xcode#

Open Xcode and create a new SwiftUI project.

Add the supabase-swift dependency.

Add the https://github.com/supabase-community/supabase-swift package to your app. For instructions, see the Apple tutorial on adding package dependencies.

Create a helper file to initialize the Supabase client. You need the API URL and the anon key that you copied earlier. These variables will be exposed on the application, and that's completely fine since you have Row Level Security enabled on your database.

Supabase.swift

import Supabase

let supabase = SupabaseClient(
  supabaseURL: URL(string: "YOUR_SUPABASE_URL")!,
  supabaseKey: "YOUR_SUPABASE_ANON_KEY"
)

Set up a SwiftUI view to manage logins and sign ups. Users should be able to sign in using a magic link.

AuthView.swift

import SwiftUI
import Supabase

struct AuthView: View {
  @State var email = ""
  @State var isLoading = false
  @State var result: Result<Void, Error>?

  var body: some View {
    Form {
      Section {
        TextField("Email", text: $email)
          .textContentType(.emailAddress)
          .textInputAutocapitalization(.never)
          .autocorrectionDisabled()
      }

      Section {
        Button("Sign in") {
          signInButtonTapped()
        }

        if isLoading {
          ProgressView()
        }
      }

      if let result {
        Section {
          switch result {
          case .success:
            Text("Check your inbox.")
          case .failure(let error):
            Text(error.localizedDescription).foregroundStyle(.red)
          }
        }
      }
    }
    .onOpenURL(perform: { url in
      Task {
        do {
          try await supabase.auth.session(from: url)
        } catch {
          self.result = .failure(error)
        }
      }
    })
  }

  func signInButtonTapped() {
    Task {
      isLoading = true
      defer { isLoading = false }

      do {
        try await supabase.auth.signInWithOTP(
            email: email,
            redirectTo: URL(string: "io.supabase.user-management://login-callback")
        )
        result = .success(())
      } catch {
        result = .failure(error)
      }
    }
  }
}

The example uses a custom redirectTo URL. For this to work, add a custom redirect URL to Supabase and a custom URL scheme to your SwiftUI application. Follow the guide on implementing deep link handling.

Account view#

After a user is signed in, you can allow them to edit their profile details and manage their account.

Create a new view for that called ProfileView.swift.

ProfileView.swift

struct ProfileView: View {
  @State var username = ""
  @State var fullName = ""
  @State var website = ""

  @State var isLoading = false

  var body: some View {
    NavigationStack {
      Form {
        Section {
          TextField("Username", text: $username)
            .textContentType(.username)
            .textInputAutocapitalization(.never)
          TextField("Full name", text: $fullName)
            .textContentType(.name)
          TextField("Website", text: $website)
            .textContentType(.URL)
            .textInputAutocapitalization(.never)
        }

        Section {
          Button("Update profile") {
            updateProfileButtonTapped()
          }
          .bold()

          if isLoading {
            ProgressView()
          }
        }
      }
      .navigationTitle("Profile")
      .toolbar(content: {
        ToolbarItem(placement: .topBarLeading){
          Button("Sign out", role: .destructive) {
            Task {
              try? await supabase.auth.signOut()
            }
          }
        }
      })
    }
    .task {
      await getInitialProfile()
    }
  }

  func getInitialProfile() async {
    do {
      let currentUser = try await supabase.auth.session.user

      let profile: Profile = try await supabase.database
        .from("profiles")
        .select()
        .eq("id", value: currentUser.id)
        .single()
        .execute()
        .value

      self.username = profile.username ?? ""
      self.fullName = profile.fullName ?? ""
      self.website = profile.website ?? ""

    } catch {
      debugPrint(error)
    }
  }

  func updateProfileButtonTapped() {
    Task {
      isLoading = true
      defer { isLoading = false }
      do {
        let currentUser = try await supabase.auth.session.user

        try await supabase.database
          .from("profiles")
          .update(
            UpdateProfileParams(
              username: username,
              fullName: fullName,
              website: website
            )
          )
          .eq("id", value: currentUser.id)
          .execute()
      } catch {
        debugPrint(error)
      }
    }
  }
}

Models#

In ProfileView.swift, you used 2 model types for deserializing the response and serializing the request to Supabase. Add those in a new Models.swift file.

Models.swift

struct Profile: Decodable {
  let username: String?
  let fullName: String?
  let website: String?

  enum CodingKeys: String, CodingKey {
    case username
    case fullName = "full_name"
    case website
  }
}

struct UpdateProfileParams: Encodable {
  let username: String
  let fullName: String
  let website: String

  enum CodingKeys: String, CodingKey {
    case username
    case fullName = "full_name"
    case website
  }
}

Launch!#

Now that you've created all the views, add an entry point for the application. This will verify if the user has a valid session and route them to the authenticated or non-authenticated state.

Add a new AppView.swift file.

AppView.swift

struct AppView: View {
  @State var isAuthenticated = false

  var body: some View {
    Group {
      if isAuthenticated {
        ProfileView()
      } else {
        AuthView()
      }
    }
    .task {
      for await state in await supabase.auth.onAuthStateChange() {
        if [.initialSession, .signedIn, .signedOut].contains(state.event) {
          isAuthenticated = state.session != nil
        }
      }
    }
  }
}

Update the entry point to the newly created AppView. Run in Xcode to launch your application in the simulator.

Bonus: Profile photos#

Every Supabase project is configured with Storage for managing large files like photos and videos.

Add PhotosPicker#

Let's add support for the user to pick an image from the library and upload it. Start by creating a new type to hold the picked avatar image:

AvatarImage.swift

import SwiftUI

struct AvatarImage: Transferable, Equatable {
  let image: Image
  let data: Data

  static var transferRepresentation: some TransferRepresentation {
    DataRepresentation(importedContentType: .image) { data in
      guard let image = AvatarImage(data: data) else {
        throw TransferError.importFailed
      }

      return image
    }
  }
}

extension AvatarImage {
  init?(data: Data) {
    guard let uiImage = UIImage(data: data) else {
      return nil
    }

    let image = Image(uiImage: uiImage)
    self.init(image: image, data: data)
  }
}

enum TransferError: Error {
  case importFailed
}

Add PhotosPicker to Profile page#

ProfileView.swift

struct ProfileView: View {
  @State var username = ""
  @State var fullName = ""
  @State var website = ""

  @State var isLoading = false

+ @State var imageSelection: PhotosPickerItem?
+ @State var avatarImage: AvatarImage?

  var body: some View {
    NavigationStack {
      Form {
+        Section {
+          HStack {
+            Group {
+              if let avatarImage {
+                avatarImage.image.resizable()
+              } else {
+                Color.clear
+              }
+            }
+            .scaledToFit()
+            .frame(width: 80, height: 80)
+
+            Spacer()
+
+            PhotosPicker(selection: $imageSelection, matching: .images) {
+              Image(systemName: "pencil.circle.fill")
+                .symbolRenderingMode(.multicolor)
+                .font(.system(size: 30))
+                .foregroundColor(.accentColor)
+            }
+          }
+        }

        Section {
          TextField("Username", text: $username)
            .textContentType(.username)
            .textInputAutocapitalization(.never)
          TextField("Full name", text: $fullName)
            .textContentType(.name)
          TextField("Website", text: $website)
            .textContentType(.URL)
            .textInputAutocapitalization(.never)
        }

        Section {
          Button("Update profile") {
            updateProfileButtonTapped()
          }
          .bold()

          if isLoading {
            ProgressView()
          }
        }
      }
      .navigationTitle("Profile")
      .toolbar(content: {
        ToolbarItem {
          Button("Sign out", role: .destructive) {
            Task {
              try? await supabase.auth.signOut()
            }
          }
        }
      })
+      .onChange(of: imageSelection) { _, newValue in
+        guard let newValue else { return }
+        loadTransferable(from: newValue)
+      }
    }
    .task {
      await getInitialProfile()
    }
  }

  func getInitialProfile() async {
    do {
      let currentUser = try await supabase.auth.session.user

      let profile: Profile = try await supabase.database
        .from("profiles")
        .select()
        .eq("id", value: currentUser.id)
        .single()
        .execute()
        .value

      username = profile.username ?? ""
      fullName = profile.fullName ?? ""
      website = profile.website ?? ""

+      if let avatarURL = profile.avatarURL, !avatarURL.isEmpty {
+        try await downloadImage(path: avatarURL)
+      }

    } catch {
      debugPrint(error)
    }
  }

  func updateProfileButtonTapped() {
    Task {
      isLoading = true
      defer { isLoading = false }
      do {
+        let imageURL = try await uploadImage()

        let currentUser = try await supabase.auth.session.user

        let updatedProfile = Profile(
          username: username,
          fullName: fullName,
          website: website,
+          avatarURL: imageURL
        )

        try await supabase.database
          .from("profiles")
          .update(updatedProfile)
          .eq("id", value: currentUser.id)
          .execute()
      } catch {
        debugPrint(error)
      }
    }
  }

+  private func loadTransferable(from imageSelection: PhotosPickerItem) {
+    Task {
+      do {
+        avatarImage = try await imageSelection.loadTransferable(type: AvatarImage.self)
+      } catch {
+        debugPrint(error)
+      }
+    }
+  }
+
+  private func downloadImage(path: String) async throws {
+    let data = try await supabase.storage.from("avatars").download(path: path)
+    avatarImage = AvatarImage(data: data)
+  }
+
+  private func uploadImage() async throws -> String? {
+    guard let data = avatarImage?.data else { return nil }
+
+    let filePath = "\(UUID().uuidString).jpeg"
+
+    try await supabase.storage
+      .from("avatars")
+      .upload(
+        path: filePath,
+        file: data,
+        options: FileOptions(contentType: "image/jpeg")
+      )
+
+    return filePath
+  }
}

Finally, update your Models.

Models.swift

struct Profile: Codable {
  let username: String?
  let fullName: String?
  let website: String?
  let avatarURL: String?

  enum CodingKeys: String, CodingKey {
    case username
    case fullName = "full_name"
    case website
    case avatarURL = "avatar_url"
  }
}

You no longer need the UpdateProfileParams struct, as you can now reuse the Profile struct for both request and response calls.

Storage management#

If you upload additional profile photos, they'll accumulate in the avatars bucket because of their random names with only the latest being referenced from public.profiles and the older versions getting orphaned.

To automatically remove obsolete storage objects, extend the database triggers. Note that it is not sufficient to delete the objects from the storage.objects table because that would orphan and leak the actual storage objects in the S3 backend. Instead, invoke the storage API within Postgres via the http extension.

Enable the http extension for the extensions schema in the Dashboard. Then, define the following SQL functions in the SQL Editor to delete storage objects via the API:

create or replace function delete_storage_object(bucket text, object text, out status int, out content text)
returns record
language 'plpgsql'
security definer
as $$
declare
  project_url text := '<YOURPROJECTURL>';
  service_role_key text := '<YOURSERVICEROLEKEY>'; --  full access needed
  url text := project_url||'/storage/v1/object/'||bucket||'/'||object;
begin
  select
      into status, content
           result.status::int, result.content::text
      FROM extensions.http((
    'DELETE',
    url,
    ARRAY[extensions.http_header('authorization','Bearer '||service_role_key)],
    NULL,
    NULL)::extensions.http_request) as result;
end;
$$;

create or replace function delete_avatar(avatar_url text, out status int, out content text)
returns record
language 'plpgsql'
security definer
as $$
begin
  select
      into status, content
           result.status, result.content
      from public.delete_storage_object('avatars', avatar_url) as result;
end;
$$;

Next, add a trigger that removes any obsolete avatar whenever the profile is updated or deleted:

create or replace function delete_old_avatar()
returns trigger
language 'plpgsql'
security definer
as $$
declare
  status int;
  content text;
  avatar_name text;
begin
  if coalesce(old.avatar_url, '') <> ''
      and (tg_op = 'DELETE' or (old.avatar_url <> coalesce(new.avatar_url, ''))) then
    -- extract avatar name
    avatar_name := old.avatar_url;
    select
      into status, content
      result.status, result.content
      from public.delete_avatar(avatar_name) as result;
    if status <> 200 then
      raise warning 'Could not delete avatar: % %', status, content;
    end if;
  end if;
  if tg_op = 'DELETE' then
    return old;
  end if;
  return new;
end;
$$;

create trigger before_profile_changes
  before update of avatar_url or delete on public.profiles
  for each row execute function public.delete_old_avatar();

Finally, delete the public.profile row before a user is deleted. If this step is omitted, you won't be able to delete users without first manually deleting their avatar image.

create or replace function delete_old_profile()
returns trigger
language 'plpgsql'
security definer
as $$
begin
  delete from public.profiles where id = old.id;
  return old;
end;
$$;

create trigger before_delete_user
  before delete on auth.users
  for each row execute function public.delete_old_profile();

At this stage you have a fully functional application!

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