YOUserbase/GroupOverviewPage.xaml.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace YOUserbase;

public partial class GroupOverviewPage : ContentPage {
    public int _index = 0;

    private string details;
    private string name;
    public string Details { get => details; set => SetProperty(ref details, value); }
    public string Name { get => name; set => SetProperty(ref name, value); }

    public GroupOverviewPage() {
        InitializeComponent();
        groups.ItemsSource = Data.Groups;
    }

    private async void OnAdd(object sender, EventArgs e) {
        await Navigation.PushAsync(new CreateGroupPage());
    }

    private async void OnDeleteItem(object sender, EventArgs e) {
        Button btn = (Button) sender;
        var id = Int32.Parse(btn.ClassId);
        var group = Data.Groups.FirstOrDefault(usr => usr.Id == id);
        var action = await DisplayAlert("Irreversible action", "Do you really want to delete this group?\nThis will also delete every User that that belongs to this group", "Yes", "No");
        if(action) {
            while(Data.Users.FirstOrDefault(usr => usr.WorkingGroup == group) != null) {
                Data.Users.Remove(Data.Users.FirstOrDefault(usr => usr.WorkingGroup == group));
            }
            Data.Groups.Remove(group);
        }
    }

    private async void OnEditItem(object sender, EventArgs e) {
        Button btn = (Button) sender;
        var id = Int32.Parse(btn.ClassId);
        var group = Data.Groups.FirstOrDefault(usr => usr.Id == id);
        Console.WriteLine("there");
        await Navigation.PushAsync(new CreateGroupPage(group));
        Console.WriteLine("and there");
    }

    protected bool SetProperty<T>(ref T field, T newValue, [CallerMemberName] string propertyName = null) {
        if(!Equals(field, newValue)) {
            field = newValue;
            return true;
        }

        return false;
    }
}