davidbarone / Dbarone.Net.Validation

A .NET object validation library using attribute annotations.

Dbarone.Net.Validation

A .NET object validation library using attribute annotations.

Validating objects is a common task in enterprise applications. This library uses attributes to annotate a class to describe a set of validation rules. Objects can then be validated, and any validation results obtained. Validation attributes are generally places on properties of a class, with the exception of the MethodValidatorAttribute which is placed on methods.

Validation Attributes

A number of validation attributes have been included for common validation tasks:

Validator	Description
NotNullValidator	Validates whether a property has a null value
NumericRanteValidator	Validates that a numeric property is within a range of values
RegExValidatorAttribute	Validates that a string property matches a RegEx expression
RequiredValidator	Validates that a property has a value. Checks for empty strings
StringLengthValidator	Validates that a string property has a length between min and max values
MethodValidator	Provides a mechanism to add a custom validation method
ObjectValidator	Applies validation on a child object

ValidationManager

The ValidationManager class provides the core validation functions:

Method	Purpose
Validate	Validates an object. Throws a ValidationException error if validation fails
PeekValidate	Does not throw an error, but returns the validation results, which can then be inspected.
IsValid	Returns true if the object passes validation.

Example code

using Dbarone.Net.Validation;

/// <summary>
/// Test entity class to run validation tests on.
/// </summary>
public class Customer
{
    public int Id { get; set; }

    [RequiredValidator]
    [StringLengthValidator(Min = 1, Max = 6)]
    public string CustomerCode { get; set; } = default!;

    [RequiredValidator]
    public string CustomerName { get; set; } = default!;

    [RequiredValidator]
    [RegExValidator(Pattern = "(A|B|C)")]
    public string Rating { get; set; } = default!;

    [NumericRangeValidator(Min = 0, Max = 1000)]
    public int CreditLevel { get; set; } = default!;
}

public class CustomerService
{
    public void AddCustomer(Customer customer)
    {
        if ValidationManager.IsValid(customer) {
            // OK - persist customer to database etc.
            ...
            ...
        }
    }
}