Question

Hello and thanks for any assistance.

using .Net 3.5 C#;

Say i have about 10 methods that all follow the same pattern

Using 3 as an example:

public Customer CreateCustomer(Customer c) { .. }
public Car CreateCar(Car c) { .. }
public Planet CreatePlanet(Planet p) { ..}

the internal logic of each method has the exact same pattern.

IE:

public Customer CreateCustomer(Customer c)
{
Log.BeginRequest(c, ActionType.Create); 
Validate(customer);
WebService.Send(Convert(c));
Log.EndRequest(c, ActionType.Create); 
}

public Car CreateCar(Car c)
{
Log.BeginRequest(c, ActionType.Create); 

Validate(c);

WebService.Send(Convert(c));

Log.EndRequest(c, ActionType.Create); 
}

The same is true with CreatePlanet and the other 7 methods.

Can these methods be re-written, they all follow the same pattern, and I feel like I am missing something… Is there is another level of abstraction that could be derived?

Question: How should this be re-written to take advantage of proper architecture pattens?

Thanks,
Steven

Answer 1

It seems like a case that fits the template pattern. You can make all of the entities implement the same interface/base and execute the action against the interface.

I assume the only part that has to know the actual type is Validate(). It can be solved by two ways:

1. Having the interface/base declare Validate and then implement it in each concrete entity.
2. Define a strategy mapping between type of concrete entity and the actual validate strategy.

Example using base class abstract validation –

Base of entity, where it has internal service for create and abstract definition for validate:

public abstract class EntityBase
{
    protected abstract void Validate();

    protected void Create(EntityBase c)
    {
        Log.BeginRequest(c, ActionType.Create);
        c.Validate();
        WebService.Send(Convert(c));
        Log.EndRequest(c, ActionType.Create); 
    }
}

Concrete implementor with validate functionality:

public class Customer : EntityBase
{
    private int year;

    public Customer(int year)
    {
        this.year = year;
    }

    public void CreateCustomer(Customer c)
    {
        Create(c);
    }

    protected override void Validate()
    {
        if (year < 1900)
        {
            throw new Exception("Too old");
        }
    }
}

I didn’t see in the original code what Create returns so I changed it to void to make the example clear