# Radzen.FluentValidation

A small Blazor integration that connects FluentValidation with Radzen forms. It provides a Radzen-compatible validator component (RadzenFluentValidator) that attaches to a RadzenTemplateForm, uses FluentValidation validators (sync or async), and displays validation messages in Radzen style (inline or as tooltip popups).

## Features
- Integrates FluentValidation with RadzenTemplateForm.
- Per-field validation and message display.
- Supports synchronous and asynchronous validation.
- Optional tooltip popup display with configurable position.
- Supports custom IValidator and IValidatorSelector injection.

## Installation
- Add the project to your solution or reference the compiled assembly.
- Ensure you have Radzen.Blazor and FluentValidation referenced in your Blazor project.

Register FluentValidation validators in DI (example in Startup.cs / Program.cs):
```cs
// Register your validators
services.AddTransient<IValidator<MyModel>, MyModelValidator>();
```

## Usage

Example model and validator:
```cs
public class MyModel
{
    public string Name { get; set; }
}

public class MyModelValidator : AbstractValidator<MyModel>
{
    public MyModelValidator()
    {
        RuleFor(x => x.Name).NotEmpty().WithMessage("Name is required.");
    }
}
```

Example Blazor (Razor) usage with RadzenTemplateForm:
```razor
@using Radzen.Blazor
@using Radzen.FluentValidation

<RadzenTemplateForm TItem=MyModel Data=model Submit=OnSubmit>
    <FluentValidator />
    <ValidationSummary />
    <RadzenStack Orientation=Orientation.Vertical Gap="8px">
        @* Name field *@
        <RadzenFormField Text=@Strings[nameof(AccountModel.Name)]>
            <ChildContent>
                <RadzenTextBox @bind-Value=@Item.Name Name="input-name" />
            </ChildContent>
            <Helper>
                <RadzenFluentValidator Component="input-name" />
            </Helper>
        </RadzenFormField>
    </RadzenStack>
</RadzenTemplateForm>

@code {
    private MyModel model = new MyModel();

    void OnSubmit()
    {
        // form submit logic
    }
}
```

Notes:
- The `Component` parameter should match how you identify/find the Radzen field within the form (the component name used by your IRadzenForm implementation).
- Use `AsyncMode=true` to run validators via `ValidateAsync`.
- You can set `Validator` explicitly or let the component resolve an `IValidator<TModel>` from DI.
- `Selector` can be provided to control which FluentValidation rules run.

## Behavior
- The component attaches to the form's EditContext and uses a ValidationMessageStore to publish FluentValidation errors to Blazor's validation system.
- Shows combined messages for a field and updates when validation state changes.

## Contributing
Contributions are welcome. Open issues or PRs with improvements or bug fixes.

## License
This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.