R – Base business class: is it bad

Architecturebusiness-objectsnet

I would like to create my base business class, something like EntityBase, to have some common behavior, such as implementing interface to track changes in the object (IsNew, IsDirty) and INotifyPropertyChanges interface.

But many people say it's a bad idea to have a base business class and derive all your business objects from it. Usually they say that it is bad to have presentation code in the entity class. But I think it's just a theory. What is bad in practice? They say: try it yourself. No more arguments usually.

So what do you guys think? Is it good or bad? If bad, why? Please, try to be a practical person, not theoretic.

Best Answer

A lot of people subscribe to the idea of Single Responsibility Principle, which says that a class should only have a single area of responsibility. By building state tracking, rendering and so forth into a common base class, you'll certainly violate the SRP. If you class handles many tasks, it will have many reasons to change.

Related Solutions

C# – Calling the base constructor in C#

Modify your constructor to the following so that it calls the base class constructor properly:

public class MyExceptionClass : Exception
{
    public MyExceptionClass(string message, string extrainfo) : base(message)
    {
        //other stuff here
    }
}

Note that a constructor is not something that you can call anytime within a method. That's the reason you're getting errors in your call in the constructor body.

.net – What’s the difference between struct and class in .NET

In .NET, there are two categories of types, reference types and value types.

Structs are value types and classes are reference types.

The general difference is that a reference type lives on the heap, and a value type lives inline, that is, wherever it is your variable or field is defined.

A variable containing a value type contains the entire value type value. For a struct, that means that the variable contains the entire struct, with all its fields.

A variable containing a reference type contains a pointer, or a reference to somewhere else in memory where the actual value resides.

This has one benefit, to begin with:

value types always contains a value
reference types can contain a null-reference, meaning that they don't refer to anything at all at the moment

Internally, reference types are implemented as pointers, and knowing that, and knowing how variable assignment works, there are other behavioral patterns:

copying the contents of a value type variable into another variable, copies the entire contents into the new variable, making the two distinct. In other words, after the copy, changes to one won't affect the other
copying the contents of a reference type variable into another variable, copies the reference, which means you now have two references to the same somewhere else storage of the actual data. In other words, after the copy, changing the data in one reference will appear to affect the other as well, but only because you're really just looking at the same data both places

When you declare variables or fields, here's how the two types differ:

variable: value type lives on the stack, reference type lives on the stack as a pointer to somewhere in heap memory where the actual memory lives (though note Eric Lipperts article series: The Stack Is An Implementation Detail.)
class/struct-field: value type lives completely inside the type, reference type lives inside the type as a pointer to somewhere in heap memory where the actual memory lives.

Best Answer

Related Solutions

C# – Calling the base constructor in C#

.net – What’s the difference between struct and class in .NET

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