Intercept <a href> navigation

[Jinjinov]

I have a note taking app where users can take notes containing links that get converted to <a href>.

The default behavior of any desktop Blazor app (Photino, MAUI, WPF, WinForms) using any kind of webview is to open the link in the same webview window, but I want external links to open in the default browser.

Adding target="_blank" rel="noopener noreferrer" to <a href> opens the link in a new webview window, which is not what I want.

For:
Microsoft.AspNetCore.Components.WebView.Maui.BlazorWebView
Microsoft.AspNetCore.Components.WebView.Wpf.BlazorWebView
Microsoft.AspNetCore.Components.WebView.WindowsForms.BlazorWebView
which wrap
Microsoft.UI.Xaml.Controls.WebView2
Microsoft.Web.WebView2.Wpf.WebView2
Microsoft.Web.WebView2.WinForms.WebView2

it is possible to intercept <a href> navigation in MAUI Blazor hybrid and open it in the default browser like so:

public MainPage()
{
    InitializeComponent();
    blazorWebView.UrlLoading += OnUrlLoading;
}
private void OnUrlLoading(object? sender, UrlLoadingEventArgs e)
{
    Uri uri = e.Url;
    if (!uri.Host.Contains("0.0.0.0"))
    {
        e.UrlLoadingStrategy = UrlLoadingStrategy.CancelLoad;
        Browser.OpenAsync(uri, BrowserLaunchMode.External);
    }
}

and in WPF like so:

public MainWindow()
{
    InitializeComponent();
    blazorWebView.UrlLoading += OnUrlLoading;
}
private void OnUrlLoading(object? sender, UrlLoadingEventArgs e)
{
    Uri uri = e.Url;
    if (!uri.Host.Contains("0.0.0.0"))
    {
        e.UrlLoadingStrategy = UrlLoadingStrategy.CancelLoad;
        Process.Start(new ProcessStartInfo(uri.ToString()) { UseShellExecute = true });
    }
}

I would like to do the same in Photino, even if only on Linux.

[andrew-bedford]

I'm facing the same issue, except that any link with a target won't open, not even in the same window. I've also tried using onclick="window.open...", but no luck.

[MikeYeager]

Photino is not designed to fire up an external browser. You can spin up a new process in C# to open a browser, but spinning up a new process is not something we're looking at doing in Photino.

[Jinjinov]

What I am asking in this issue is not to

fire up an external browser

or

spin up a new process in C#

I am asking to intercept the <a href> click, which I believe is within the scope of this library.

It is also something that is supported in

• class BlazorWebView in namespace Microsoft.AspNetCore.Components.WebView.Wpf
• class BlazorWebView in namespace Microsoft.AspNetCore.Components.WebView.WindowsForms
• class BlazorWebView in namespace Microsoft.AspNetCore.Components.WebView.Maui

with blazorWebView.UrlLoading += OnUrlLoading;

So I think that my request is not unreasonable. This feature could be used for many things beside spinning up a new process.

[MikeYeager]

@Jinjinov I'm confused. You said, "The default behavior of any desktop Blazor app (Photino, MAUI, WPF, WinForms) using any kind of webview is to open the link in the same webview window, but I want external links to open in the default browser." If that's not what you want to do, can you explain your use case in more detail? If you want to intercept the click on the link, you can add an event handler in JavaScript. Or you could use a custom scheme for the URL to handle the click in C#.

[Jinjinov]

I would like you to add an event UrlLoading on the main Blazor window which triggers when the user clicks on <a href>.

The point of Blazor is to use C# instead of JS wherever possible. Yes, I can use JS to handle clicks on <a href>, but even if they are hardcoded the solution requires unnecessary extra work.

But in my case the <a href> are not known at compile time, because they come from the Markdown when users write their notes which are saved in my app.

Right now I am using code that slows down the conversion from Markdown to Html to add JS to <a href> when users save their Markdown notes and I display them as Html.

Subscribing to <a href> clicked event would simplify and speed up my app. This can be used to for any number of useful features, including opening an external browser.

[Jinjinov]

@philippjbauer Any chance that you take a look at this? Does it still deserve the "wontfix" label?

[andrew-bedford]

@Jinjinov , I don't know if it will help you but I ended up simply using PyQt with a QWebEngineView (see repository). It's all I really needed in my case.

[Jinjinov]

@andrew-bedford Thank you!

My project uses Photino in just 5% of the code, the rest relies heavily on C# https://github.com/Jinjinov/OpenHabitTracker