Design patterns for Conditional Views.

[pawan chopra]

Hi All,

I am working on one shopping application. I have a header which acts like a container. Sometimes it acts like a container for recommended product, sometimes for advertisement. Right now I am conditionally changing innerHTML of header container for displaying advertisement or recommended product. I may add more categories to display in the header. I kind of feel that this if else will grow with time. Specially every category for example advertisement has more priority than recommended product. So if I get both from the feed I will show advertisement not recommended product. I would like to know what will be the good design for implementing such kind of thing. Is there any design pattern?

[Roberto Perillo]

Howdy, Pawan!

Well champ, this "if-else" thing isn't certainly the best way. Especially in the actual page itself: it is better to keep this logic away from it and have it on the server side. It is better to use HTML/XHTML/JSF/JSP only to display things. Eventually, you might have an "if" there (e.g. to verify if the user can see a particular button), but the less logic you have on pages, the better.

But I think we could use more details to give you some advice. It looks like we're talking about something like an e-commerce, right? You have a page, and you have a header that displays things. Categories have higher priority than products. How do you decide what is going to be displayed on the header? I mean, is it based on the product that is being displayed? How does it work?