Check single property

[kronic]

How can i check one property of an object and not the whole object?

[bartoszlenar]

Hi @kronic

I guess you're looking for the Member command?

You have it fully documented here: https://github.com/bartoszlenar/Validot/blob/main/docs/DOCUMENTATION.md#member

Also I have it described with examples on my blog: https://lenar.dev/posts/crafting-model-specifications-using-validot#validating-members

[kronic]

@bartoszlenar I meant something else. Simple example

public class UserModel
{
    private readonly IValidator<UserModel> _validator;
    private string? _name;
    private string? _email;
    private int _age;

    public UserModel()
    {
        Specification<UserModel> userModelSpecification = static s => s
            .Member(static m => m.Name, static v => v.NotEmpty().LengthBetween(2, 5))
            .Member(static m => m.Age, static v => v.Between(18, 99))
            .Member(static m => m.Email, static v => v.Contains("@"));

        _validator = Validator.Factory.Create(userModelSpecification);
    }

    public string? Name
    {
        get => _name;
        set
        {
            _name = value;
            //how validate only property Name
            _validator.Validate()
        }
    }
    public string? Email
    {
        get => _email;
        set
        {
            _email = value;
            //how validate only property Email
            _validator.Validate()
        }
    }
    public int Age
    {
        get => _age;
        set
        {
            _age = value;
            //how validate only property Age
            _validator.Validate()
        }
    }
}

[bartoszlenar]

That's not possible. What I would do...

1. Create specification per property (and thus, a validator per property). And then if you need also one that bundles them all, you can just merge them (see this section: https://lenar.dev/posts/crafting-model-specifications-using-validot#merging-and-extending-specifications)

2. Validate as you do, but fail if the validation result contain errors only within a specific path. Something like

public int Age
    {
        get => _age;
        set
        {
            _age = value;

            if (_validator.Validate(_age).MessageMap.ContainsKey("Age")) throw new Exception();

        }
    }

I don't know your use case, but in general I would recommend NOT to place your validation logic in setters. Make your model anemic and validate it externally. Again - that's only a general advice, as I have no idea about your requirements.