Chapter 16 Page 576 Question

jsymons · September 23rd, 2009, 02:19 PM

Imar,

Quick question. To quote your book on page 576 right below figure 16-8 it says "If you haven't set any preferred genres, or none of them contain any reviews or you're no logged in, you get the message shown in Figure 16-9." I noticed the following two things:

1. The message in Figure 16-9 contains a different text string then what was entered within the PlaceHolder at the top of page 575. No biggie here, just bringing it to your attention.

2. More importantly, I didn't get the said message for preferred genres that didn't contain any reviews. To test this, I explicitly selected genres that didn't have any reviews as my preference and requested the page. The genres showed up boldface with no reviews underneath them. Shouldn't I have gotten the message instead?

Additionally, even when some preferred genres had reviews and others did not, the ones that didn't still showed up boldface as in Figure 16-8 on page 576. I got the impression that if there is no reviews for a preferred genre, then that genre shouldn't end up on the page all together.

Any thoughts on this would be greatly appreciated.

Thanks,

John

Imar · September 23rd, 2009, 04:45 PM

Hi there,

Regarding #1: yes, correct. The image doesn't correctly reflect the text you entered in step 2. I'll have that added to the errata section. But as you say, no biggie.

#2: I can see where the confusion comes from. Basically, when you have selected at least one genre in the Profile page, it shows up on that page, regardless of the number of reviews attached to it. So, you may see seven emtpty genres with no reviews if you selected those on the profile page. This was more or less intended / by design.
I can see how your idea is more natural. Fortunately, it's easy to implement. Just limit the Genres to those that have at least one review:

Code:

var favGenres = from genre in myDatabaseContext.Genres
                     orderby genre.Name
                     where Profile.FavoriteGenres.Contains(genre.Id)
                     && genre.Reviews.Count() > 0
                     select new { genre.Name, genre.Reviews };

Now, when a Genre does not have a Review, it won't show up in the list. This in turn means you see the message if no review (and thus no empty Genre header) shows up.

Cheers,

Imar

jsymons · September 23rd, 2009, 06:12 PM

Imar,

An easy fix indeed to get that behavior. I just had to convert the one line in your C# example from && genre.Reviews.Count() > 0 to And genre.Reviews.Count > 0 _ because my code was written in VB.

Thanks again,

John

Imar · September 25th, 2009, 03:20 AM

Excellent, glad it's working...

Imar