Is it possible to add support for IQueryAttributable to non-Shell pages?

[maonaoda]

All that said, let's not add IQueryAttributable support for non-Shell apps now. And if/when users start asking for the feature, we can circle back to this conversation!

I was planning to add support for using IQueryAttributable myself, but I found that PopupPage is not public, which limits this approach.
Are there any other options at this point, such as continuing to use the V1 OnPresenting, or supporting migration for non-Shell scenarios?

[Skarzag]

I guess this could help to fix my problem ?
#3029

[maonaoda]

I currently only use my custom package, which adds IQueryAttributable for non-Shell navigation...

[pictos]

Can you guys share a project with what you trying to do? I can start working with that

@Skarzag @maonaoda

[bijington]

@pictos it might not be a full solution but something I worked on above ⬆️

[pictos]

So, I make it work from your sample @Skarzag, thanks for that. For your end you will need to access the inner Dictionary<Type,Type> on PopupService.

[UnsafeAccessor(UnsafeAccessorKind.StaticField, Name = "viewModelToViewMappings")]
public static extern ref Dictionary<Type, Type> GetUnsafeviewModelToViewMappings(PopupService service);

@bijington thanks for looking into it, but I found an easier way, IMHO. I think isn't hard to add it to MCT, as you can see in the image `IQueryAttributable` can be used outside Shell context.

static class MyPopupService
{
	public static async Task ShowPopupData<T>(this INavigation nav, IDictionary<string, object> data)
	{
		var provider = IPlatformApplication.Current!.Services;
		var popupService = (PopupService)provider.GetService<IPopupService>()!;

		var mapping = UnsafeAccessorClass.GetUnsafeviewModelToViewMappings(popupService);
		
		var content = (Popup)provider.GetRequiredService(mapping[typeof(T)]);

		if (content.BindingContext is IQueryAttributable viewModel)
		{
			viewModel.ApplyQueryAttributes(data);
		}

		nav.ShowPopup(content);
	}
}

[Skarzag]

I like the way this whole conversation is going 😊

[pictos]

@Skarzag , btw I'm not sure if the team would like to support this feature or when it will be released (if they want to), but you can use this code on your project to unblock you

[TheCodeTraveler]

We don't own IQueryAttributable. It is an interface created by the .NET MAUI team specifically to support Shell.

We implemented IQueryAttributable for Popup because it is a View and thus requires IQueryAttributable support, otherwise Popup would behave in unexpected ways when working with Shell navigation.

We cannot implement IQueryAttributable support outside of Shell because that breaks its contract created + owned by the .NET MAUI engineering team. It would lead to breaking changes and unforeseen behavior in CommunityToolkit.Maui in future .NET MAUI updates.

There already exist many ways to pass data into a Popup, the same way there already exist many ways to pass data into any .NET MAUI View. Adding a novel way that is outside the scope of IQueryAttributable adds unnecessary debt and maintenance to our library.

We will not be adding IQueryAttributable support for non-Shell functionality.

[maonaoda]

Basically, it’s like this. I didn’t take other possible cases into consideration.
My main goal is to initialize the ViewModel based on the parameters before the page is displayed.

Since the Popup’s title and content change depending on the category passed in through the parameters,
they need to be set accordingly in advance.

		if(popupContent.BindingContext is IQueryAttributable queryAttributable && shellParameters is not null)
		{
			queryAttributable.ApplyQueryAttributes(shellParameters);
		}

1084ba4#diff-07ec5bc1fab15d5f259161e0e9890b9441ad17cc6683556ce90f014ce2633dd1

---

In other words, this is what onPresenting used to do before:

var resultObject = await popupService.ShowPopupAsync<CustomDialogViewModel>(onPresenting =>
{
    onPresenting.PerformDialogInfo(dialogType, customContent);
});

Now it has been moved to ApplyQueryAttributes and looks like this:

public sealed class CustomDialogViewModel : BindableBase, IDestructible, IQueryAttributable
...
public void ApplyQueryAttributes(IDictionary<string, object> query)
{
    if (query.TryGetValue("DialogType", out var dialogTypeObj)
        && dialogTypeObj is DialogType dialogType)
    {
        var customContent = query.TryGetValue("CustomContent", out var customContentObj)
            && customContentObj is string contentStr
            ? contentStr
            : null;

        PerformDialogInfo(dialogType, customContent);
    }
}

[pictos]

I know what you want to, but I would like to have a sample project that I can mess with and implement it (:

Like, setup a project with a popup and passing the parameters that you want, don't matters if the project doesn't build. Looking how you would like to consume the api and having a project that I can mess with it's a good start point. I can't use the sample project because it's all Shell based

[bijington]

I know what you want to, but I would like to have a sample project that I can mess with and implement it (:

Like, setup a project with a popup and passing the parameters that you want, don't matters if the project doesn't build. Looking how you would like to consume the api and having a project that I can mess with it's a good start point. I can't use the sample project because it's all Shell based

This isn't the sample you are looking for but I had this PR which introduced shell based navigation for non shell based apps. #2740

Another thought I had to workaround this issue was to scope the popup and inject data in through constructor injection. I'll have a play with this but it might not be as elegant as building into the toolkit

[Skarzag]

Yes this is exactly what i need and the OP need i guess.

Before with the navigation there was :

• await popupService.ShowPopupAsync(onPresenting => ...);
  and now there is no option to do the same.

here is a sample i just made with 2 style of attempt to pass data.

I'm stuck, i can't update to .net 10 i can't update community toolkit.
PopupV2NavigationWithParameters.zip

[TheCodeTraveler]

and now there is no option to do the same.

Yes, there is.

Subscribe to the Popup.Opened event and add the action you need to your event handler.

var popup = new Popup();
popup.Opened += HandlePopupOpened;

void HandlePopupOpened(object sender, EventArgs e)
{
  // Code you need to execute when Popup opens
}

[Skarzag]

I don't understand this answer (with, every time i read it, no complete example at all that cover the problem).
The action I need ? Like... getting my data from another object somewhere in my app ?
Yes i can store my popup call parameters in a static variable somewhere all this time if needed. I can do that. I can do bad code.

Goal is to improve the toolkit so none of us felt throw on the side of the road.

Shell users got an elegant and practical "shellParameters" in the ShowPopupAsync function parameters but others (Navigation users) could not and should create shitty pattern to get there popup instantiation parameters ? :/

[TheCodeTraveler]

We don't own IQueryAttributable. It is an interface created by the .NET MAUI team specifically to support Shell.

We implemented IQueryAttributable for Popup because it is a View and thus requires IQueryAttributable support, otherwise Popup would behave in unexpected ways when working with Shell navigation.

We cannot implement IQueryAttributable support outside of Shell because that breaks its contract created + owned by the .NET MAUI engineering team. It would lead to breaking changes and unforeseen behavior in CommunityToolkit.Maui in future .NET MAUI updates.

There already exist many ways to pass data into a Popup, the same way there already exist many ways to pass data into any .NET MAUI View. Adding a novel way that is outside the scope of IQueryAttributable adds unnecessary debt and maintenance to our library.

We will not be adding IQueryAttributable support for non-Shell functionality.

[Skarzag]

Thanks @pictos, you opened my eye on something. I found a solution.

This was the second part of my answer before i found a solution :
_

@TheCodeTraveler, i don't understand why you're using so much time & energy to just don't answer and throw our problem away with a "There already exist many ways to pass data into a Popup".
JUST. GIVE. US. A GOOD ONE ?
I don't care about IQueryAttributable or whatever, i want you, really good experimented programmers to give us, the pleb, some prerafined solution. Give us the light.
I mean, in my opinion, this is the whole point of a toolkit. Prerafined solution made by the upper grade programmers to help on common problems.

We had a PopupV1 with a solution and a tutorial to pass data for shell and non-shell and now we have PopupV2 with a solution and a tutorial to pass data for shell but NOT for non-shell.
I don't know... i beg you, could you please update the doc with these "many ways" that are in the room with us ?

You're driving me crazy sir.

_

New answer :
With the help of @pictos now i found one. How?
await _popupService.ShowPopupAsync(nav, laPopup); //don't exist
await _popupService.ShowPopupAsync(nav, laPopup); //don't exist
await nav.ShowPopupAsync(laPopup); //exist <<<<

I don't know why this call with a view parameter exist as an extension method of Navigation & Page but not in the PopupService itself.
So now i'm getting a transiant popup from the container that i initiate with data and... pass it to the viewmodel via the famous Opened event. Then nav.ShowPopupAsync();

I've updated my repo for those in needs : https://github.com/Skarzag/PopupV2NavigationWithParameters

To finish, what's the point with closing a discussion we're not done with :/