Issues related to parameters passed through URI protocol activation

[abenadar]

Current behavior

Given the outdated documentation for UWP, I couldn't get URI activation to work with WinUI as the ActivationKind was never Protocol and the arguments empty:

protected override void OnLaunched(LaunchActivatedEventArgs e)
{
    if (e.UWPLaunchActivatedEventArgs.Kind == ActivationKind.Protocol)
    {
      e.UWPLaunchActivatedEventArgs.Arguments...

Instead I settled for searching the parameter in the envrionment arguments:

Environment
    .GetCommandLineArgs()
    .FirstOrDefault(s => s
        .StartsWith("appuri://")))

While URI launch itself works on Windows and iOS (haven't tested Android), the parameter is never present on iOS.
Is there a workaround I can use to have any given parameter to be actually present?

Example URI: appuri://?param=test

PS: I also noticed that URI activation leads to an app freeze immediately after the splashscreen if the app isn't currently running, which requires navigation from and back to the app once to make it work. This might be on my end though; I am still investigating.

Expected behavior

URI activation causes parameters to be present.

How to reproduce it (as minimally and precisely as possible)

No response

Workaround

none

Works on UWP/WinUI

None

Environment

Uno.WinUI / Uno.WinUI.WebAssembly / Uno.WinUI.Skia

NuGet package version(s)

5.6.0-dev.1235

Affected platforms

iOS

IDE

Visual Studio 2022

IDE version

17.12.3

Relevant plugins

No response

Anything else we need to know?

No response

[abenadar]

Related

[jeromelaban]

The URL component is provided to the app through OnActivated, not OnLaunched:

See this part:

uno/src/Uno.UI/UI/Xaml/Application.iOS.cs

Lines 59 to 69 in 8d836a8

	if (launchOptions.TryGetValue(UIApplication.LaunchOptionsUrlKey, out var urlObject))
	{
	_preventSecondaryActivationHandling = true;
	var url = (NSUrl)urlObject;
	if (TryParseUri(url, out var uri))
	{
	OnActivated(new ProtocolActivatedEventArgs(uri, ApplicationExecutionState.NotRunning));
	handled = true;
	}
	}
	else if (launchOptions.TryGetValue(UIApplication.LaunchOptionsShortcutItemKey, out var shortcutItemObject))

[abenadar]

Many thanks, I now have a solution based on overriding FinishedLaunching like so:

    public override bool FinishedLaunching(UIKit.UIApplication application, Foundation.NSDictionary launchOptions)
    {
        var result = string.Join(Environment.NewLine, launchOptions ?? []);
       
        //...

        return base.FinishedLaunching(application, launchOptions);
    }

However, I am still running into these issues:

1. The 'UIApplicationLaunchOptionsURLKey' key is only set when the app is booted via url and not when it's currently running (FinishedLaunching is called anyhow though).
2. Perhaps unrelated, but the app just fails to continue after it's launched through URL, somewhere after or during the call to base.FinishedLaunching. This is surely on my end, but I'm wondering whether:

• This is known behaviour caused by some speicific issues I cna look after;
• There is a way to keep the Xamarin debugger running after termination or before app startup so I can look into the issue myself.

Any help on this would be welcome as well.

[jeromelaban]

Many thanks, I now have a solution based on overriding FinishedLaunching like so:

OnLaunched did not provide you with the URL information? If so, there may be something that needs fixing.

This is known behaviour caused by some speicific issues I cna look after;

I don't think there's anything specific related to the url launching and any failure to continue at this time.

There is a way to keep the Xamarin debugger running after termination or before app startup so I can look into the issue myself.

At this time, there isn't that I know of. This was a feature that was supported by VS for mac at some point (the app can wait for the debugger to start), but it's not available in VS nor VS Code.

[abenadar]

OnLaunched did not provide you with the URL information? If so, there may be something that needs fixing.

OnLaunched hasn't done this at all, hence use a workaround using Environment.GetCommandLineArgs() on Windows. Since this didn't provide any arguments on iOS I built another workaround overriding FinishedLaunching() based on your answer. However, even here the behaviour on a physical device is as described above under 1. The only LaunchOption is '[UIApplicationLaunchOptionsURLKey, app://?param=hello]' and is only present when the app is started from scratch, not when already running.

As for the rest, I almost feared so, but thanks for the input anyway.