Why all it's methods and properties were declared as static?
This is an abstract class, so why do wee need statics?
All objects that need to use those methods or/and properties inherit this class any way so they can access them.

They are declared as static because they are used by other static methods.

Take for example:

protectedstaticstring CurrentUserIP
This is used by the InsertComment method, which is itself static. If CurrentUserIP were not static, you wouldn't be able to use it in the InsertComment method.

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This insertcommand method in Comment class
( public class Comment : BaseArticle , where BaseArticle inherits BizObject class)

So if we change the definition of CurrentUserIP to public , there will be no problem to access it from all classess that inherit BizObject.

So insertCommand can use it as: this.CurrentUserIP.

update:
Well , I've noticed only now that InsertCommand is also static...

Is it a good practice to use so many statics methods and classes?

Isn't that exactly what I pointed out in my first reply? Perhaps you missed that.

Using statics is a great idea if you do not want to have to create an instance of a class to use its methods.

Calling Comment.InsertComment(blah blah blah) is more straightforward than doing Comment comment = new Comment(), setting the properties, then calling comment.Insert(). However, there's nothing stopping you from doing it that way if you want.

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Thanks.
I got the point.

My pleasure, anytime.

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As I mentioned earlier, i want to remove all static declaration from all businesses classes.
But I don't want to change much the original design, doing so I've encountered some problems that I hope you will help me to solve.

First problem I've encountered changing Category class.
In this class there is a property with it's getter:

As you can see I cannot use Article.GetArticles(...)
What would be the best option in my case scenario?
Should I pass Article class' instance as parameter to Category instance?
(In this case i will pass and store whole Article class for just one method)

Maybe I should use delegates with events to point to GetArticles method in Article instance?

Maybe I should completely change the design to meet my needs (that i don't want to do) or maybe partial change involving just the part of retrieving Articles from category?

Or, maybe you should use the statics to avoid the problem you've created for yourself by trying to eliminate them.

There is nothing wrong with using statics; and in some cases, like with the tbh design there are distinct advantages of using them; you don't have to have an instance of an object to call a method and you don't need to pass a reference around as a parameter.

Marco has provided us an elegant, extensible and scalable design; before you discard it, make sure you fully understand it.


Steve

I guess I'm with Steve on this. I don't get your aversion to static classes/methods. To me, it seems like you're trying to create a solution to a non-existent problem.

There are cases where you may get away with using pure instance methods, but there are others in which it just doesn't make sense. For example, it makes no sense to create a default instance of an article just to call the GetArticles() method on it.

If you really want to do that, you would probably want to consider looking into an entirely different design pattern, like Factory or Respository. TBH uses the Active Record pattern, which doesn't lend itself well to non-static usages.

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Yes, I totally agree with you on this.

And after meeting more problems like this I am coming to a conclusion that if i want to avoid using static I need to completely change the design.