H3rm.Validation 6.0.1

ValidationAttributeBase Class

Overview

ValidationAttributeBase is an abstract class located in the Validation namespace. It serves as the base class for validation attributes, extending the functionality of ValidationAttribute from System.ComponentModel.DataAnnotations.

Features

• ThrowException Property: Determines whether an exception is thrown when validation fails.
• ValidationCondition Method: Abstract method to be overridden by derived classes to provide specific condition logic.
• DefaultErrorMessage Property: Holds the default error message to be used when validation fails, allowing derived classes to provide specific error messages.
• IsValid Method: Evaluates the provided value against the condition and returns a ValidationResult that encapsulates the result of the validation.

Usage

Defining a Custom Validation Attribute

Create a derived class and override the ValidationCondition to define the validation logic.

namespace Validation
{
    public class CustomValidationAttribute : ValidationAttributeBase
    {
        protected override Func<string, bool> ValidationCondition => value => !string.IsNullOrEmpty(value);

        protected override string DefaultErrorMessage => "Value cannot be null or empty";
    }
}

Applying the Custom Validation Attribute

Apply the custom validation attribute to properties or fields of your classes.

public class SampleClass
{
    [CustomValidation]
    public string SampleProperty { get; set; }
}

Configuration

Set ThrowException to true if an exception should be thrown when the validation fails.

[CustomValidation(ThrowException = true)]
public string SampleProperty { get; set; }

API

Properties

• bool ThrowException { get; set; }
• string DefaultErrorMessage { get; }

Methods

• Func<string, bool> ValidationCondition { get; }
• ValidationResult IsValid(object value, ValidationContext validationContext)

Conclusion

ValidationAttributeBase allows for the creation of custom validation attributes with configurable conditions, error messages, and exception handling, providing enhanced validation capabilities in the .NET ecosystem.