YOUserbase/CreateUserPage.xaml.cs

using System.Collections.ObjectModel;
using UIKit;

namespace YOUserbase;

public partial class CreateUserPage : ContentPage {

    private User user;

    public CreateUserPage() {
        InitializeComponent();
        groupPicker.ItemsSource = new List<string>(Data.Groups.Select(x => x.Name));
    }

    public CreateUserPage(User user) {
        InitializeComponent();
        this.user = user;
        FirstnameEntry.Text = user.Firstname;
        LastnameEntry.Text = user.Lastname;
        birthdatePicker.Date = user.BirthDate;
        FullTimeSwitch.IsToggled = user.IsFullTime;
        DetailsEntry.Text = user.Details;
        IsExternalCheck.IsChecked = user.IsExternal;
        IsRemoteCheck.IsChecked = user.IsRemote;
        NbProjectsStepper.Value = user.NbProjects;
        groupPicker.ItemsSource = new List<string>(Data.Groups.Select(x => x.Name));
        groupPicker.SelectedIndex = Data.Groups.IndexOf(user.WorkingGroup);
        btnCreate.Text = "Save";
        contentPage.Title = "Edit user";
    }

    private async void OnCreateClicked(object sender, EventArgs e) {
        var isValid = true;
        string text = FirstnameEntry.Text;
        errFirstname.Text = "";
        if(String.IsNullOrWhiteSpace(text)) {
            isValid = false;
            errFirstname.Text = "First name cannot be empty";
        } else if(text.Length > 20) {
            isValid = false;
            errFirstname.Text = "First name cannot be longer than 20 characters";
        }
        text = LastnameEntry.Text;
        errLastname.Text = "";
        if(String.IsNullOrWhiteSpace(text)) {
            isValid = false;
            errLastname.Text = "Last name cannot be empty";
        } else if(text.Length > 20) {
            isValid = false;
            errLastname.Text = "Last name cannot be longer than 20 characters";
        }
        var date = birthdatePicker.Date;
        errBirthDate.Text = "";
        if(DateTime.Compare(date, DateTime.Today) > 0) {
            isValid = false;
            errBirthDate.Text = "Birth date cannot be in the future";
        }
        errGroup.Text = "";
        if(groupPicker.SelectedIndex == -1) {
            errGroup.Text = "You have to select a valid group";
        }
        errDetails.Text = "";
        if(DetailsEntry.Text.Length > 100) {
            errDetails.Text = "Detail cannot be longer than 100 characters";
        }
        if(isValid) {
            // Update
            if(user != null) {
                var usr = Data.Users.FirstOrDefault(usr => usr.Id == user.Id);
                usr.Firstname = FirstnameEntry.Text;
                usr.Lastname = LastnameEntry.Text;
                usr.BirthDate = birthdatePicker.Date.Date;
                usr.WorkingGroup = Data.Groups[groupPicker.SelectedIndex];
                usr.Details = DetailsEntry.Text;
                usr.IsFullTime = FullTimeSwitch.IsToggled;
                usr.IsExternal = IsExternalCheck.IsChecked;
                usr.IsRemote = IsRemoteCheck.IsChecked;
                usr.NbProjects = (int) NbProjectsStepper.Value;
            } else { // Create
                Data.Users.Add(new User {
                    Firstname = FirstnameEntry.Text,
                    Lastname = LastnameEntry.Text,
                    BirthDate = birthdatePicker.Date.Date,
                    WorkingGroup = Data.Groups[groupPicker.SelectedIndex],
                    Details = DetailsEntry.Text,
                    IsFullTime = FullTimeSwitch.IsToggled,
                    IsExternal = IsExternalCheck.IsChecked,
                    IsRemote = IsRemoteCheck.IsChecked,
                    NbProjects = (int) NbProjectsStepper.Value,
                });
            }
            await Navigation.PopAsync();
        }
    }

    void OnStepperChanged(System.Object sender, Microsoft.Maui.Controls.ValueChangedEventArgs e) =>
        lblNbProj.Text = ((Stepper) sender).Value.ToString();
}