[Problem/Bug]: SourceChanged doesn't detect view-source:

[RicardoTM05]

What happened?

I'm trying to display the correct url when view source is solicited just like normal browsers do.

The problem is that when I do, for example: webView->Navigate(L"view-source:http://example.com/");

webView->add_SourceChanged(
	Callback<ICoreWebView2SourceChangedEventHandler>(
		[this](ICoreWebView2* sender, ICoreWebView2SourceChangedEventArgs* args) -> HRESULT
		{
			wil::unique_cotaskmem_string uri;
			sender->get_Source(&uri);
			RmLogF(rm, LOG_DEBUG, L"SourceChanged - source URL: %s", uri);

			return S_OK;
		}
	).Get(), nullptr
);

It logs:
SourceChanged - source URL: http://example.com/
without "view-source:".

In fact, no event returns the URL string with the view-source string included but the NewWindowRequested event, where this:

webView->add_NewWindowRequested(
	Callback<ICoreWebView2NewWindowRequestedEventHandler>(
		[this](ICoreWebView2* sender, ICoreWebView2NewWindowRequestedEventArgs* args) -> HRESULT
		{
			wil::unique_cotaskmem_string destinationUri;
			args->get_Uri(&destinationUri);
			wil::unique_cotaskmem_string initialUri;
			sender->get_Source(&initialUri);
			RmLogF(rm, LOG_DEBUG, L"NewWindowRequested - Initial URL: %s", initialUri);
			RmLogF(rm, LOG_DEBUG, L"NewWindowRequested - Destination URL: %s", destinationUri);

			return S_OK;
		}
	).Get(), nullptr
);

Correctly logs:
NewWindowRequested - Initial URL: http://example.com/
NewWindowRequested - Destination URL: view-source:http://example.com/

An event that has similar options is the NavigationStarting one:

webView->add_NavigationStarting(
	Callback<ICoreWebView2NavigationStartingEventHandler>(
		[this](ICoreWebView2* sender, ICoreWebView2NavigationStartingEventArgs* args) -> HRESULT
		{
			wil::unique_cotaskmem_string initialUri;
			sender->get_Source(&initialUri);
			wil::unique_cotaskmem_string destinationUri;
			args->get_Uri(&destinationUri);
			RmLogF(rm, LOG_DEBUG, L"NavigationStarting - Initial URL: %s", initialUri);
			RmLogF(rm, LOG_DEBUG, L"NavigationStarting - Destination URL: %s", destinationUri);

			return S_OK;
		}
	).Get(), nullptr
);

But that, incorrectly logs:
NavigationStarting - Initial URL: http://example.com/
NavigationStarting - Destination URL: http://example.com/

So unless the navigation comes from a new window request (like pressing Ctrl + U), then it's not possible to display the correct url. For example, it is impossible to do so if the user navigates from a view-source page to a normal page, then returns to the view-source page through GoBack(), since the user didn't enter the url directly to an input I can read, and no event is risen that informs me that the view-source was solicited.

Ideally, all events should include the view-source string when requested.

Importance

Moderate. My app's user experience is affected, but still usable.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

143.0.3650.96

SDK Version

1.0.3650.58

Framework

Win32

Operating System

Windows 11

OS Version

No response

Repro steps

Navigate to a view-source: page using navigate()

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Don't know

Last working version (if regression)

No response

[jls28]

I agree that this is not ideal;

I also encourage you to take a look at the title changed event (or simply the result of get_DocumentTitle) :
it always report a title equal to ... the complete and correct url in this case !

Check out my application (portable, one small executable, english/french) : https://gist.github.com/jls28/70d3086ca3eca30643000c541b90654a
I think this is a very nice app to test this kind of problem and others.

[RicardoTM05]

I also encourage you to take a look at the title changed event (or simply the result of get_DocumentTitle) : it always report a title equal to ... the complete and correct url in this case !

Thank you, this works fine as a workaround.

Unfortunately it doesn't include the scheme when the very first navigation is done to a 'view-source:' URI for some reason. Still works good enough. Thank you!

By the way, I'm not closing this issue as I still consider all navigation events should report when a scheme is present on the URI, not only NewWindowRequested.

[jls28]

Unfortunately it doesn't include the scheme when the very first navigation is done

It’s probably happening because you need to wait for the TitleChanged event
before calling get_DocumentTitle().

Yes, the NewWindowRequested target URI does include the view-source:,
but after the SourceChanged event, the result of get_Source() no longer includes it.

The view-source: scheme itself seems quite artificial (it’s not really a true URI scheme).

At the JavaScript level,
document.location never contains it,
and any attempt to assign document.location to "view-source:https://example.com/"
simply throws the error: "Not allowed to load local resource: view-source:".

To summarize:

Navigating to view-source:https://example.com/
causes get_Source() and JavaScript document.location to resolve to https://example.com/ after the SourceChanged event.

After the TitleChanged event, get_DocumentTitle() returns "view-source:https://example.com/",
while JavaScript document.title remains empty.

There is another issue:

Navigating from https://example.com/ to view-source:https://example.com/
(or the reverse) does not trigger a SourceChanged event,
probably because the underlying source is actually unchanged.
However, it does trigger a history change event,
which is incorrect, since the browser history is clearly not modified.

[RicardoTM05]

It’s probably happening because you need to wait for the TitleChanged event before calling get_DocumentTitle().

No, I'm correctly listening to DocumentTitleChanged event and it doesn't include view-source on the very first navigation. Also tried checking on NavigationCompleted and same result. Also checked when requesting the context menu and same result.

Very first navigation:

Going back from another site:

Also noticed that the blob: scheme is returned correctly from get_Source with no extra logic needed.

That's correct, view-source: doesn't trigger a SourceChanged event unless you navigate from one site to another site with view-source: included. Still it doesn't detect the view-source: scheme string.

Trying different schemes have similar results as view-source:, although some make WebView2 unresponsive.