BLL Article Instance Methods

alfinmass · August 19th, 2009, 02:56 PM

I am going over the Article class and have questions about the instance methods.

The Delete method:

Code:

public bool Delete()
{
	bool success = Article.DeleteArticle(this.ID);
	if (success)
		this.ID = 0;
	return success;
}

Why do we just set the ID property to zero and not reset all properties to their original values if the deletion is successful? Imagine that we have an Article object with all the information (holding the comments and everything) and we call the delete method. We would still have a lot of information in the object that is not really reflecting the record in the database. Is there a purpose for this?

The IncrementViewCount method:

Code:

public bool IncrementViewCount()
{
	return Article.IncrementArticleViewCount(this.ID);
}

Why don't we update the object's ViewCount property? So we increment the ViewCount in the database by 1, but the property in the object is not reflecting that value. However, in the Approve method we do update the object's Approved property. This seems at least inconsistent.

The Rate method:

Code:

public bool Rate(int rating)
{
	return Article.RateArticle(this.ID, rating);
}

Same thing as with the IncrementViewCount method. Why don't we update the TotalRating property?

Anyone else has found this awkward?

Thanks for any light on this.

Lee Dumond · August 19th, 2009, 04:10 PM

You will notice that in some of the static methods that are called by these various instance methods, the cache is purged, and in others it is not.

That should give you a big clue.

alfinmass · August 19th, 2009, 05:54 PM

Hi Lee,

thanks as usual for answering my posts. First, I like the "purged is cached", hahahahahahaha Don't let your brain go so fast man...

Purging the cache will just cause the next article to be created to get fresh data from the database. My point was on what happens to the objects that are already created, since they are left holding information that is no longer valid.

For example let us consider the delete method. Let us say that you have filled the Article object fields with all the appropriate data and then you call the instance method Delete(). That will delete the article in the database, and the comments because of the cascading foreign key setup, but the Article object will still have the same values that are no longer on the database on its fields. The only thing that has changed is the _id field which now has a value of 0.

I don't know if filling up the fields before calling the delete method would be a common use of the object, but we cannot assume that it is not, can we? So shouldn't we reset all the fields to their original values when we call the delete method so we have an 'empty' article and all the related objects are orphaned so the garbage collector can collect them?

In the case of the rating and incrementing views is more like the object field would hold the wrong rate or view count after calling those methods.

Again it is not so much what happens when we try to load the data again, but what happens to the data we currently have loaded in the object.

Thanks. :-)