[Proposal] PopupService #981
Description
Feature name
PopupService
Link to discussion
Progress tracker
- Android Implementation
- iOS Implementation
- MacCatalyst Implementation
- Windows Implementation
- Tizen Implementation
- Unit Tests
- Samples
- Documentation
Summary
The following proposal provides the ability to register and show popups with associated view models. It will also allow this to be done from a view model.
Motivation
To make it easier to show popups from a view model.
Detailed Design
PopupService
using System.ComponentModel;
using CommunityToolkit.Maui.Views;
namespace Popups;
public class PopupService
{
private readonly IServiceProvider serviceProvider;
private readonly static IDictionary<Type, Type> viewModelToViewMappings = new Dictionary<Type, Type>();
public PopupService(IServiceProvider serviceProvider)
{
this.serviceProvider = serviceProvider;
}
public static void AddTransientPopup<TPopupView, TPopupViewModel>(IServiceCollection services)
where TPopupView : Popup
where TPopupViewModel : INotifyPropertyChanged
{
viewModelToViewMappings.Add(typeof(TPopupViewModel), typeof(TPopupView));
services.AddTransient(typeof(TPopupView));
services.AddTransient(typeof(TPopupViewModel));
}
public Task<object> ShowPopupAsync<TViewModel>()
{
var viewModelType = typeof(TViewModel);
var viewModel = (TViewModel)this.serviceProvider.GetService<TViewModel>();
if (viewModel is null)
{
throw new InvalidOperationException($"Unable to resolve type {viewModelType} please make sure that you have called RegisterPopup");
}
return ShowPopupAsync<TViewModel>(viewModel);
}
public Task<object> ShowPopupAsync<TViewModel>(TViewModel viewModel)
{
var viewModelType = typeof(TViewModel);
var view = (Popup)this.serviceProvider.GetRequiredService(viewModelToViewMappings[viewModelType]);
view.BindingContext = viewModel;
// TODO: Do we need to provide an override for determine the main page? Or we at least need to verify there is a main page.
return Application.Current.MainPage.ShowPopupAsync(view);
}
}ServiceCollectionExtension
public static class ServiceCollectionExtensions
{
public static IServiceCollection AddTransientPopup<TPopupView, TPopupViewModel>(this IServiceCollection services)
where TPopupView : Popup
where TPopupViewModel : INotifyPropertyChanged
{
PopupService. AddTransientPopup<TPopupView, TPopupViewModel>(services);
return services;
}
}Usage Syntax
// Registration in MauiProgram.cs
builder.Services.AddTransientPopup<ConfirmationPopupView, ConfirmationPopupViewModel>();
// Showing of popup from a VM
popupService.ShowPopupAsync<ConfirmationPopupViewModel>();Drawbacks
It is heavily MVVM focused
Alternatives
No response
Unresolved Questions
No response