• Roman Funk (28/28) Oct 19 2022 Hello,
• Steven Schveighoffer (9/46) Oct 20 2022 Just a thought, this may be nothing as I've never used the hunt

Roman Funk <roman.funk66 gmail.com> writes:

Hello,

I started playing with D and the hunt-framework. But I bumped 
into an error using Validation.

```d
module app.forms.LoginForm;
import hunt.validation;
import hunt.framework.http.Form;

class LoginForm : Form {
     mixin MakeForm;
      Email
     string name;
      Length(3,8)
     string password;
}

```
The error looks like that:

`../hunt/validation/DeclDef.d-mixin-41(54,108): Error: undefined 
identifier arg`

When I remove the parameters from ` Length`, it compiles.

I tried the `dicoth` example application, but I get the same 
error for the validation used there.

I use this compiler: DMD64 D Compiler v2.100.2
under Linux.

My current D knowledge is not sufficient to fix the bug. No idea 
how the annotation and mixin templates work together here. I 
didn't find any documentation, how to write custom annotations.

Can somebody give me a hint?

BR Roman

Steven Schveighoffer <schveiguy gmail.com> writes:

On 10/19/22 3:00 PM, Roman Funk wrote:
 Hello,
 
 I started playing with D and the hunt-framework. But I bumped into an 
 error using Validation.
 
 ```d
 module app.forms.LoginForm;
 import hunt.validation;
 import hunt.framework.http.Form;
 
 class LoginForm : Form {
      mixin MakeForm;
       Email
      string name;
       Length(3,8)
      string password;
 }
 
 ```
 The error looks like that:
 
 `../hunt/validation/DeclDef.d-mixin-41(54,108): Error: undefined 
 identifier arg`
 
 When I remove the parameters from ` Length`, it compiles.
 
 I tried the `dicoth` example application, but I get the same error for 
 the validation used there.
 
 I use this compiler: DMD64 D Compiler v2.100.2
 under Linux.
 
 My current D knowledge is not sufficient to fix the bug. No idea how the 
 annotation and mixin templates work together here. I didn't find any 
 documentation, how to write custom annotations.
 
 Can somebody give me a hint?

Just a thought, this may be nothing as I've never used the hunt 
framework, but try putting the mixin at the end of the class. Sometimes 
mixins can introspect the type they are being mixed into, which means 
the compiler has to build the rest of the type *first*. Although D 
should be able to forward reference all of this, at some point you have 
to have some kind of ordering in order to properly introspect a partly 
built type.

-Steve