- I will explain you section by section clean code examples below.
###Sustainability With References
- First of all, we will give a bad code example and then we will make it better step by step.
- First of all, I will give you examples on writing reference-based code that is necessary to write clean code.
- We will first examine the
Customer Managerclass and then theProduct Managerclass.
####program.cs
class Program
{
static void Main(string[] args)
{
CustomerManager customerManager = new CustomerManager();
customerManager.Add(new Entities.Customer { CustomerName = "Alican", CustomerCode = "AFWQFW2213", CustomerIdentity = "2589631725" }, Enums.DatabaseTypes.Oracle);
ProductManager productManager = new ProductManager(new NhProductDal(),new StockControllerServiceAdapter());
productManager.Add(new Entities.Product() { Name = "Soap", Quantity = 102, Barcode = "AFWQ212352" });
}
}####CustomerManager.cs
public class CustomerManager
{
public void Add(Customer customer, DatabaseTypes databaseTypes)
{
Utility.Validate(new CustomerValidator(),customer);
CustomerDal customerDal = new CustomerDal(databaseTypes);
customerDal.Add(customer);
}
public void AddByOtherBusiness()
{
}
}- The Add method, which is a member of the
Customer ManagerClass, takes two parameters from theCustomerClass type and theDatabaseTypesEnum type.
####Utility.cs
public static class Utility
{
/// <summary>
/// Verify to object using the validator.
/// </summary>
/// <param name="validator">Validator implemented from IValidator.</param>
/// <param name="entity">Entity to be verified</param>
public static void Validate(IValidator validator, object entity)// First Parameter is : CustomerValidator Second Parameter is : Entity(Customer)
{
var result = validator.Validate(entity);
if (result.Errors.Count > 0)
{
throw new ValidationException(result.Errors);
}
}
}- There is a
Validatemethod belonging to theutilityclass. Because theValidatemethod usesIValidator(Fluent Api-Fluent Validation) type, it checks the incoming entity according to the relevant validator class.
####CustomerValidator.cs
public class CustomerValidator:AbstractValidator<Customer>
{
public CustomerValidator()
{
RuleFor(x => x.CustomerName).NotEmpty().When(x=>x.CustomerIdentity=="123").WithMessage("CustomerName field not be empty!");
RuleFor(x => x.CustomerCode).NotEmpty().WithMessage("CustomerCode field not be empty!");
RuleFor(x => x.CustomerIdentity).NotEmpty().WithMessage("Customer Identity field not be empty!");
RuleFor(x => x.CustomerIdentity).Must(BeEven);
}
private bool BeEven(string arg)
{
return true;
}
}-
As we have seen in
Customer Validation, if we want to validate a entity, we must create avalidatorclass of it. -
AbstractValidator <Customer>structure comes from fluent validation and implements the IValidate interface. -
If we go back to the
CustomerManagerclass, you will see that we are going to theCustomerDalclass.
####CustomerDal.cs
public class CustomerDal
{
DatabaseTypes _databaseTypes;
public CustomerDal(DatabaseTypes databaseTypes)
{
_databaseTypes = databaseTypes;
}
public void Add(Customer customer)
{
if (_databaseTypes==DatabaseTypes.Oracle)
{
Console.WriteLine(customer.CustomerName+" Customer added to Database with Oracle.");
}
else
{
Console.WriteLine(customer.CustomerName+" Customer added to Database with Mssql.");
}
}
public bool CustomerExist(Customer customer)
{
return true;
}
}- The
CustomerDalclass works with the Database Types given to it.(Mssql or Oracle etc.)
####DatabaseTypes.cs
public enum DatabaseTypes
{
Oracle,SqlServer
}- Let's take a look at the
Customer Managerclass again.
-You will see the customerDal.Add(customer); code and it will add the person to the database according to the database type given previously.
-
Next time we'll look at how we can make this code better.
-
If you can't wait, please check out the code in the SustainabilityWithReferences folder.
-
Alican Yılmaz