[Proposal] Tupled model

[VBAndCs]

We add many trivial classes corresponding to each view, like this one needed for login view:

public class LoginModel {
    [Required] [UIHint("email")]
    public string Email { get; set; }

    [Required] [UIHint("password")]
    public string Password { get; set; }
}

It will be better if we can express it as a record like this:

public class LoginModel (
    [Required] [UIHint("email")] string Email,
    [Required] [UIHint("password")] string Password 
)

But this needs to allow mutable records, which I wish to reconsider!

This can be more better, if it can be expressed inline as a tuple-like record, to be used directly in the view:

@model ([Required] [UIHint("email")] string Email,
    [Required] [UIHint("password")] string Password)

And in the post method, dependency injection can resolve the arguments from the tupled model object:

[HttpPost]
public IActionResult Login(string Email,
    string Password)

If this is not easy for some reason, we can mark the action method with [Tupled] attribute to direct the view to inspect the view for the record properties.

this can be called tupled model or anonymous model, and Razor should generate it as a full class:

public class SomeCompilerName {
    [Required] [UIHint("email")]
    public string string Email { get; set; }

    [Required] [UIHint("password")]
    public string Password { get; set; }
}

and the view will be compiled to:

@model SomeCompilerName

Another approach is just to use tuples:

@model (string Email, string Password)

But we need tag helpers to apply the effect of the [Required] and [UIHint("email")] directly on the html input elements used for email and password, which can be easier with some tag helpers, say asp-required and asp-hint.
In this case, we just define the same tuple as a parameter for the action method:

[HttpPost]
public IActionResult Login((string Email, string Password) data)

[davidfowl]

This should be part of the records discussion happening in c# 9

[VBAndCs]

@davidfowl
I don't think so, for three reasons:

1. Records are immutable.
2. Razor has its own syntax and compiler and generates C# classes at runtime, so it can do it independent of the programming language.
3. ASP.Net Core uses attributes intensively, which is not the case of general C# code, so attributed records don't have w wide demand in C#.
   Thanks

[danroth27]

@VBAndCs Razor & MVC is based on C#. We don't independently design language extensions to C# that are specific to Razor. The right place to discuss this is with the C# folks.