Compiler error with mixed content in onclick attribute

[panda-eye]

I have a line in Teachers.cshtml:
<button onclick="window.location.href = '/teacher/@(teacher.Id)/';">More info...</button>
After compilation I have the following line in Teachers.g.cs (/obj/Debug/netstandart2.0/Pages/):
builder.AddAttribute(24, "onclick", (Microsoft.AspNetCore.Blazor.Components.BindMethods.GetEventHandlerValue<Microsoft.AspNetCore.Blazor.UIMouseEventArgs>() + "window.location.href" + " =" + " \'/teacher/" + (teacher.Id) + "/\';" + ()));
And an error message:

CS1525 Invalid expression term ")"

[panda-eye]

The same result if I remove whitespaces

[codeinstinct]

Here's what I would do:

Change this
<button onclick="window.location.href = '/teacher/@(teacher.Id)/';">More info...</button>

to
<button onclick=@Navigate(teacher.Id)>More info...</button>

Add this line at the top of the .cshtml (after the @page "<route>" directive)
@inject Microsoft.AspNetCore.Blazor.Services.IUriHelper UriHelper

Add this method Navigate to the functions block

@functions {
    private void Navigate(string id)
    {
        UriHelper.NavigateTo($"/teacher/{id}");
    }
}

[ghost]

Believe this issue might be a similar problem with double and single quote combinations not being correctly escaped as raised in issue #1527

[SteveSandersonMS]

Thanks for reporting this, @panda-eye.

I think it's a separate issue from #1527, because it can be reproduced without involving any quotes, e.g.:

@{ var a = "a"; }
<button onclick="@(a)b">More info...</button>

Codegen output:

// Compiler error due to empty parens:
builder.AddAttribute(1, "onclick", (Microsoft.AspNetCore.Blazor.Components.BindMethods.GetEventHandlerValue<Microsoft.AspNetCore.Blazor.UIMouseEventArgs>(a) + "b" + ()));

Looks like we don't correctly handle mixed content within event handler attributes at the moment.

Workaround: Use C# string interpolation instead, e.g.:

<button onclick=@($"window.location.href = '/teacher/{teacher.Id}/';")>

Adding to backlog.

[TanayParikh]

Closing as dup of dotnet/razor#7684