I have no idea if bug of what is wrong here (issue since Popup v2)

[Sebastian1989101]

I have base classes for my ViewModels. In my project, one ViewModel loads data from a SQLite database via a repository, and another receives its model data through a query parameter. Both use the same popup for page filter settings.

However, only the repository-based ViewModel returns the updated data; the query-based ViewModel always returns unchanged data. Since the only difference is the base ViewModel in use (I’ve tested the exact same page/ViewModel with both base classes), this makes no sense to me. Switching to the repository-based base fixes the popup issue compared to the query-based one. Also, downgrading to Popup v1 fixes the issue immediately.

I’m out of ideas—would appreciate any hints on why this happens and how to resolve it.

Repository based, working, ViewModel:

using System.ComponentModel;
using CommunityToolkit.Maui.Extensions;
using CommunityToolkit.Mvvm.Input;
using MyApp.Helpers;
using MyApp.Models.Settings;
using MyApp.Pages.Popups;
using MyApp.Pages.Popups.SettingsPopup;
using MyApp.Repositories.Base;
using Newtonsoft.Json;

namespace MyApp.ViewModels.Base;

public abstract partial class SearchableRepositoryDataViewModel<TData, TViewModel> : BaseViewModel, IBaseDataViewModel
    where TData : ISearchable
    where TViewModel : SearchableRepositoryDataViewModel<TData, TViewModel>
{
    private string _lastSearchTerm = string.Empty;
    
    protected readonly ILogger<TViewModel> logger;

    protected IAppSettings AppSettings;
    protected IDatabaseRepository<TData> DatabaseRepository;

    protected virtual string checklistSettingsPrefix => typeof(TData).Name;

    [ObservableProperty] private TData[]? _allData;

    [ObservableProperty] private string _filter;

    [ObservableProperty] private CollectablePageSettings _pageSettings = new();

    [ObservableProperty] private TData[] _data = [];

    protected SearchableRepositoryDataViewModel(ILogger<TViewModel> logger, IAppSettings appSettings, IDatabaseRepository<TData> databaseRepository, string filter = "")
    {
        this.logger = logger;
        AppSettings = appSettings;
        DatabaseRepository = databaseRepository;
        _filter = filter;

        Initialize();
    }

    protected abstract IOrderedEnumerable<TData> OrderData(IEnumerable<TData> data);

    protected virtual Task DataLoaded()
    {
        return Task.CompletedTask;
    }

    protected virtual IEnumerable<TData> PrefilterAllData(TData[] data) => data;

    protected virtual void LoadAdditionalChecklistSettings(SafeDictionary<string, object?> settings)
    {

    }

    protected virtual void ResetAdditionalChecklistSettings()
    {

    }

    protected virtual void StoreAdditionalChecklistSettings(SafeDictionary<string, object?> settings)
    {

    }

    protected virtual Task<IEnumerable<TData>> GetAllDataFromRepository()
    {
        return DatabaseRepository.GetAllAsync();
    }

    partial void OnFilterChanged(string value)
    {
        if (string.IsNullOrEmpty(value))
            SearchCommand.Execute(null);
    }

    private void Initialize()
    {
        PageSettings!.LoadData(checklistSettingsPrefix, AppSettings.ChecklistSettings, supportsGrouping: false, 
            showDoneVisible: typeof(TData).IsSubclassOf(typeof(DefaultProgressBaseModel)));
        
        LoadAdditionalChecklistSettings(AppSettings.ChecklistSettings);
        Task.Run(() =>
            {
                GetAllDataFromRepository().ContinueWith(async data =>
                    {
                        AllData = (await data).ToArray();
                        await DataLoaded();
                        SearchCommand.Execute(null);
                    });
            });
    }

    [RelayCommand]
    private void Search()
    {
        try
        {
            if (AllData == null)
                return;
            
            if (Data != null && Data.Any() && _lastSearchTerm == Filter)
                return;

            _lastSearchTerm = Filter;
            logger.LogInformation($"Search for term: {_lastSearchTerm}");

            var entries = PrefilterAllData(AllData);
            if (PageSettings.ShowDoneVisible && PageSettings.ShowDoneIndex != 0)
            {
                entries = entries.Where(e =>
                    (PageSettings.ShowDoneIndex == 1 && (e as DefaultProgressBaseModel)?.Progress == false) ||
                    (PageSettings.ShowDoneIndex == 2 && (e as DefaultProgressBaseModel)?.Progress == true));
            }
            
            var data = (PageSettings!.SortOrderIndex == 0 ? OrderData(entries.Where(d => d.DoesMatch(_lastSearchTerm))) :
                OrderData(entries.Where(d => d.DoesMatch(_lastSearchTerm))).Reverse()).ToList();
            
            Data = data.ToArray();
        }
        catch (Exception e)
        {
            logger.LogError(e, e.Message);
        }
    }

    [RelayCommand]
    private async Task ShowSettings()
    {
        _lastSearchTerm = Guid.NewGuid().ToString();

        var popup = new CollectablePageSettingsPopup(PageSettings);
        var result = await Shell.Current.ShowPopupAsync<CollectablePageSettingsPopupResult>(popup);
        
        if (result.WasDismissedByTappingOutsideOfPopup || result.Result == CollectablePageSettingsPopupResult.Close)
            SettingsClosed();
        else if (result.Result == CollectablePageSettingsPopupResult.Reset)
            ResetSettings();
    }

    private void ResetSettings()
    {
        ResetAdditionalChecklistSettings();

        PageSettings.ShowDoneIndex = 0;
        PageSettings.SortOrderIndex = 0;
        PageSettings.SelectedSortByFilterIndex = 0;
        PageSettings.GroupEntries = false;

        if (PageSettings.SettingsPopupGroups != null && PageSettings.SettingsPopupGroups.Any())
        {
            foreach (var settingsGroup in PageSettings.SettingsPopupGroups)
                settingsGroup.Reset();
        }

        SettingsClosed();
        OnPropertyChanged(new PropertyChangedEventArgs(string.Empty));
    }

    private void SettingsClosed()
    {
        var settings = AppSettings.ChecklistSettings;
        StoreAdditionalChecklistSettings(settings);

        settings[$"{checklistSettingsPrefix}::{nameof(CollectablePageSettings.ShowDoneIndex)}"] = PageSettings!.ShowDoneIndex;
        settings[$"{checklistSettingsPrefix}::{nameof(CollectablePageSettings.SortOrderIndex)}"] = PageSettings!.SortOrderIndex;
        settings[$"{checklistSettingsPrefix}::{nameof(CollectablePageSettings.SettingsPopupGroups)}"] = JsonConvert.SerializeObject(PageSettings!.SettingsPopupGroups ?? [], new SettingsJsonConverter());

        AppSettings.ChecklistSettings = settings;
        SearchCommand.Execute(null);
    }
}

Query data based, not working, ViewModel:

using CommunityToolkit.Mvvm.Input;
using System.ComponentModel;
using CommunityToolkit.Maui.Extensions;
using MyApp.Helpers;
using MyApp.Models.Settings;
using MyApp.Pages.Popups;
using MyApp.Pages.Popups.SettingsPopup;
using Newtonsoft.Json;

namespace MyApp.ViewModels.Base;

public abstract partial class SearchableQueryAttributableViewModel<TData, TViewModel> : BaseViewModel, IBaseDataViewModel, IQueryAttributable
    where TData : ISearchable
    where TViewModel : SearchableQueryAttributableViewModel<TData, TViewModel>
{
    private string _lastSearchTerm = string.Empty;
    
    protected readonly ILogger<TViewModel> logger;

    protected IAppSettings AppSettings;

    protected virtual string checklistSettingsPrefix => typeof(TData).Name;

    [ObservableProperty] private TData[]? _allData;

    [ObservableProperty] private string _filter;

    [ObservableProperty] private CollectablePageSettings _pageSettings = new();

    [ObservableProperty] private TData[] _data = [];

    protected SearchableQueryAttributableViewModel(ILogger<TViewModel> logger, IAppSettings appSettings, string filter = "")
    {
        this.logger = logger;
        AppSettings = appSettings;
        _filter = filter;
    }

    public void ApplyQueryAttributes(IDictionary<string, object> query)
    {
        Initialize(GetDataFromQuery(query));
    }

    protected abstract TData[]? GetDataFromQuery(IDictionary<string, object> query);

    protected abstract IOrderedEnumerable<TData> OrderData(IEnumerable<TData> data);

    protected virtual Task DataLoaded()
    {
        return Task.CompletedTask;
    }

    protected virtual IEnumerable<TData> PrefilterAllData(TData[] data) => data;

    protected virtual void LoadAdditionalChecklistSettings(SafeDictionary<string, object?> settings)
    {

    }

    protected virtual void ResetAdditionalChecklistSettings()
    {

    }

    protected virtual void StoreAdditionalChecklistSettings(SafeDictionary<string, object?> settings)
    {

    }

    partial void OnFilterChanged(string value)
    {
        if (string.IsNullOrEmpty(value))
            SearchCommand.Execute(null);
    }

    private void Initialize(TData[]? data)
    {
        PageSettings!.LoadData(checklistSettingsPrefix, AppSettings.ChecklistSettings, supportsGrouping: false, 
            showDoneVisible: typeof(TData).IsSubclassOf(typeof(DefaultProgressBaseModel)));
        
        LoadAdditionalChecklistSettings(AppSettings.ChecklistSettings);
        Task.Run(async () =>
            {
                AllData = data;

                await DataLoaded();
                SearchCommand.Execute(null);
            });
    }

    [RelayCommand]
    private void Search()
    {
        try
        {
            if (AllData == null)
                return;
            
            if (Data != null && Data.Any() && _lastSearchTerm == Filter)
                return;

            _lastSearchTerm = Filter;
            logger.LogInformation($"Search for term: {_lastSearchTerm}");

            var entries = PrefilterAllData(AllData);
            if (PageSettings.ShowDoneVisible && PageSettings.ShowDoneIndex != 0)
            {
                entries = entries.Where(e =>
                    (PageSettings.ShowDoneIndex == 1 && (e as DefaultProgressBaseModel)?.Progress == false) ||
                    (PageSettings.ShowDoneIndex == 2 && (e as DefaultProgressBaseModel)?.Progress == true));
            }
            
            var data = (PageSettings!.SortOrderIndex == 0 ? OrderData(entries.Where(d => d.DoesMatch(_lastSearchTerm))) :
                OrderData(entries.Where(d => d.DoesMatch(_lastSearchTerm))).Reverse()).ToList();

            Data = data.ToArray();
        }
        catch (Exception e)
        {
            logger.LogError(e, e.Message);
        }
    }

    [RelayCommand]
    private async Task ShowSettings()
    {
        _lastSearchTerm = Guid.NewGuid().ToString();

        var popup = new CollectablePageSettingsPopup(PageSettings);
        var result = await Shell.Current.ShowPopupAsync<CollectablePageSettingsPopupResult>(popup);
        
        if (result.WasDismissedByTappingOutsideOfPopup || result.Result == CollectablePageSettingsPopupResult.Close)
            SettingsClosed();
        else if (result.Result == CollectablePageSettingsPopupResult.Reset)
            ResetSettings();
    }

    private void ResetSettings()
    {
        ResetAdditionalChecklistSettings();

        PageSettings.ShowDoneIndex = 0;
        PageSettings.SortOrderIndex = 0;
        PageSettings.SelectedSortByFilterIndex = 0;
        PageSettings.GroupEntries = false;

        if (PageSettings.SettingsPopupGroups != null && PageSettings.SettingsPopupGroups.Any())
        {
            foreach (var settingsGroup in PageSettings.SettingsPopupGroups)
                settingsGroup.Reset();
        }

        SettingsClosed();
        OnPropertyChanged(new PropertyChangedEventArgs(string.Empty));
    }

    private void SettingsClosed()
    {
        var settings = AppSettings.ChecklistSettings;
        StoreAdditionalChecklistSettings(settings);

        settings[$"{checklistSettingsPrefix}::{nameof(CollectablePageSettings.ShowDoneIndex)}"] = PageSettings!.ShowDoneIndex;
        settings[$"{checklistSettingsPrefix}::{nameof(CollectablePageSettings.SortOrderIndex)}"] = PageSettings!.SortOrderIndex;
        settings[$"{checklistSettingsPrefix}::{nameof(CollectablePageSettings.SettingsPopupGroups)}"] = JsonConvert.SerializeObject(PageSettings!.SettingsPopupGroups ?? [], new SettingsJsonConverter());

        AppSettings.ChecklistSettings = settings;
        SearchCommand.Execute(null);
    }
}

[Sebastian1989101]

Obviously I find the issue in the exact moment I post it online... seems like the shitty Popup v2 update also calls ApplyQueryAttributes over and over again like Appearing/Disappearing... not gonna lie, the Popup v2 upgrade was the worse I have ever seen in any library, espacially how badly it is documented.

[bijington]

We have a contributing guide that encourages people to be kind and respectful. I don't see this comment as fulfilling this. Please make an effort to use more respectful language in future. You can read th guide at https://github.com/CommunityToolkit/Maui/blob/main/CONTRIBUTING.md

[cat0363]

I was writing data loading logic within the NavigatedTo event in the app, and during data loading, I was displaying an indicator using Popup v2.
Popup v2 uses a different implementation method than v1, so the NavigatedTo, NavigatedFrom, Appearing, and Disappearing events are triggered when the Popup is displayed or closed.

Therefore, if you write data loading logic in the NavigatedTo event and data disposal logic in the NavigatedFrom event, v2 will trigger unintended data loading and disposal when the Popup is displayed or closed. To work around this issue, I implemented the following: I set a flag before displaying the popup, cleared the flag after displaying it, and added guard conditions to ignore the NavigatedTo and NavigatedFrom events called while the flag was set.

While it's a very low-tech approach, ignoring the unintended NavigatedTo, NavigatedFrom, Appearing, and Disappearing events triggered by displaying and closing the popup resolved this issue. Depending on the implementation, there might be a more elegant solution.