Frognar.ValidDotNet 0.1.0

ValidDotNet Library

The ValidDotNet library provides a lightweight validation framework for .NET applications, allowing you to define and apply validation rules to instances of specified types.

Table of Contents

• ValidDotNet Library
  • Table of Contents
  • Overview
  • Installation
  • Usage
    • ValidationResult
    • Validator
  • Examples
    • Creating a ValidationResult

Overview

The library consists of two main classes:

1. ValidationResult: Represents the result of a validation operation, containing a collection of errors. Instances are immutable, and a static 'valid' instance is provided for successful validations.

2. Validator<T>: A generic class for validating instances of a specified type using a set of rules. You can define custom validation rules and easily validate objects of type T.

Installation

To use ValidDotNet in your project, you can install it via NuGet Package Manager:

dotnet add package Frognar.ValidDotNet

Usage

ValidationResult

The 'ValidationResult' struct represents the outcome of a validation operation. It contains a collection of errors and provides methods to work with validation results.

Validator<T>

The 'Validator<T>' class allows you to define and apply validation rules to objects of type T. You can create a validator with an initial set of rules and then use it to validate objects.

Examples

Here are some basic examples to get you started:

Creating a ValidationResult

ValidationResult newResult = new();
ValidationResult valid = ValidationResult.valid;
ValidationResult invalid = valid.AddError("error");

Creating a Validator and Performing Validation

List<(Func<string, bool> isInvalid, string errorMessage)> rules = new() {
    (s => string.IsNullOrWhiteSpace(s), "String cannot be empty or whitespace."),
    (s => s.Length > 10, "String length should not exceed 10 characters.")
};

Validator<string> validator = new(rules);
ValidationResult validation = validator.Validate("SampleString");
if (validation.IsValid) {
    // Handle success
} else {
    // Handle errors
    string errorMessages = validation.AggregateErrors(", ");
    Console.WriteLine($"Validation failed with errors: {errorMessages}");
}

Inheritance supported!

public class OddIntsValidator() : Validator<int>([(i => i % 2 == 0, "Value must be odd")]);

License

This library is licensed under the MIT License - see the LICENSE file for details.