FluentValidation rule for null object

Question

I\'ve been trying to work out how to create a FluentValidation rule that checks if the instance of an object it\'s validating is not null, prior to validating it\'s properti

Answer 1

This is an older post, but want to update the answers to include the following from the FluentValidation documentation:

Using PreValidate

If you need to run specific code every time a validator is invoked, you can do this by overriding the PreValidate method. This method takes a ValidationContext as well as a ValidationResult, which you can use to customise the validation process.

public class MyValidator : AbstractValidator {
  public MyValidator() {
    RuleFor(x => x.Name).NotNull();
  }

  protected override bool PreValidate(ValidationContext context, ValidationResult result) {
    if (context.InstanceToValidate == null) {
      result.Errors.Add(new ValidationFailure("", "Please ensure a model was supplied."));
      return false;
    }
    return true;
  }
}

https://fluentvalidation.net/start#using-prevalidate