Not allowing for mixed content in attributes makes for excessive syntax

[KasparOrange]

This: Style=@($"background: {(shift.Person?.Id == User.Id ? Theme.Palette.Primary.Value : Theme.Palette.PrimaryDarken)};") looks ugly is confusing and JavaScript developer laughing about us. I know that's polemic, but what I am trying to allude to, is the need to use a lot of special characters and scopes to make this seemingly easy and usual task work.

Is this something that is my fault for not understanding how to use the framework correctly? Then how am I intended to do this correctly?

Is this just something hard to understand for the compiler? Then are there plans to make the developer experience better in this regard?

Also, I am new to creating issues, I know this does not fit the outline of the template issue, but I just didn't know how to fit what I wanted to say in that format. If this is not the right place for this information, I am sorry. :)

[chsienki]

Today the compiler doesn't allow 'mixed' content in attributes, which means it must be a string, or all C# code. In examples like this it gets a bit complicated because you're in C# code, creating a string that renders as javascript.

I suspect if we were to support mixed content it could make it simpler by supporting something like:

style="background: @(shift.Person?.Id == User.Id ? Theme.Palette.Primary.Value : Theme.Palette.PrimaryDarken);"

We would have to say that these kinds of mixed attributes must ultimately evaluate to have a value of string, but that still seems like something interesting worth exploring.

In the short term for this particular issue, it's probably clearer if you break it up into separate functions so the various interpolations aren't overlapping.

<div style="@GetStyleForPerson(shift.Person)" />

@code {
 
    public string GetStyleForUser(Person? person) => $"background: {GetColorForUser(userId)};";

    public string GetColorForPerson(Person? person) => person?.Id == User.Id ? Theme.Palette.Primary.Value : Theme.Palette.PrimaryDarken;
}

[jjonescz]

Duplicate of #7684?

Note that mixed content is already supported in non-component attributes, so implementation-wise it shouldn't be very difficult. Here's my prototype from a while back: #9742.