https://github.com/dzfweb/fluentspecification
A small validation library for .NET that uses a fluent interface and lambda expressions for building validations using Specification Pattern
https://github.com/dzfweb/fluentspecification
specification-pattern validations
Last synced: 10 months ago
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A small validation library for .NET that uses a fluent interface and lambda expressions for building validations using Specification Pattern
- Host: GitHub
- URL: https://github.com/dzfweb/fluentspecification
- Owner: dzfweb
- License: apache-2.0
- Created: 2017-09-27T12:55:17.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2017-09-27T16:53:49.000Z (over 8 years ago)
- Last Synced: 2025-04-08T17:53:18.111Z (10 months ago)
- Topics: specification-pattern, validations
- Language: C#
- Size: 33.2 KB
- Stars: 10
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# FluentSpecification
A small validation library for .NET that uses a fluent interface for building validations using Specification Pattern
#### In computer programming, the specification pattern is a particular software design pattern, whereby business rules can be recombined by chaining the business rules together using boolean logic. The pattern is frequently used in the context of domain-driven design.
## Benefits
- Easy to implement unit test, once you can test all specification separately;
- Easy to understand all business validation, once is more readable than a lot of "ifs" in one same code block;
- Easy to refactoring, once you can refactor only the one specification without interfere the others;
## Instalation
### Package Manager
`Install-Package DzfWeb.FluentSpecification`
### .NET CLI
`dotnet add package DzfWeb.FluentSpecification`
## Usage
#### 1- Given a Entity
```
public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
}
```
#### 2- Create all the specifications
For each business validation, create a new specification file with the validation
```
[SpecificationError(PersonValidation.InvalidName)]
public class PersonNameSpecification : Specification
{
public override bool IsSatisfiedBy(Person entity) =>
!string.IsNullOrEmpty(entity.FirstName) &&
!string.IsNullOrEmpty(entity.LastName);
}
```
```
[SpecificationError(PersonValidation.InvalidEmail)]
public class PersonEmailSpecification : Specification
{
public override bool IsSatisfiedBy(Person entity) =>
!string.IsNullOrEmpty(entity.Email) &&
new EmailAddressAttribute().IsValid(entity.Email);
}
```
#### 3- Create a validator
Create a validator grouping all the specifications
```
public class PersonValidator : Validator
{
public PersonValidator(PersonNameSpecification personNameSpecification,
PersonEmailSpecification personEmailSpecification)
: base(personNameSpecification,
personEmailSpecification)
{ }
}
```
#### 4- Use the validator
```
var result = _personValidator.IsValid(person);
```
#### 5- Get all broken specifications
```
foreach(var item in _personValidator.InvalidRules)
{
//item correspond to SpecificationErrorAttribute value defined on specification file
Console.WriteLine(item);
}
```
## Customize the validation
#### You can filter which specifications you want to use in some cases
```
var isValidToSendEmail = _personValidator
.FilterRules(typeof(PersonEmailSpecification))
.IsValid(person);
```
#### You can add parameters to be used during the validation
```
var isValidToCreate = _personValidator
.AddParameter("RestrictedEmail", "douglas.franco@dzfweb.com.br")
.IsValid(person);
```
```
[SpecificationError(PersonValidation.InvalidEmail)]
public class PersonEmailSpecification : Specification
{
public override bool IsSatisfiedBy(Person entity) =>
!string.IsNullOrEmpty(entity.Email) &&
new EmailAddressAttribute().IsValid(entity.Email) &&
entity.Email != (string)Parameters.GetValueOrDefault("RestrictedEmail", "");
}
```
## Samples
For more samples, visit:
https://github.com/dzfweb/FluentSpecification/blob/master/FluentSpecification/FluentSpecification.Test/PersonTest.cs