Sidebar: Building a Dynamic Left Side Menu
Web Commerce Today, Issue 2, September 15, 1997
Menus have a way of changing. The more detailed the menu, the more often it's likely to morph. But a detailed menu is one of the keys to enticing shoppers from your front page inside your store. How do you keep your left-side menu fresh on every page without having to change each and every Web page every time the menu changes?
1. Frames. You could employ frames. The menu appears on every page, but frame scroll bars look ugly. More serious, frames often inhibit Web search engines from indexing an entire store, and many shoppers actively dislike them.
2. Server-side image map. Our site uses an image map. We change the graphic, re-map it, upload it to the server, and it affects every page in the system. Two cautions: Make sure you employ a server-side image map; client-side image maps require code in each Web page which would need to be changed every time the map changed. Also, don't specify height and width in the IMG tag. That way the graphic can lengthen without you having to change every page. (Warning: FrontPage 2.0 specifies a height and width for every graphic unless you're very careful.) The large left side graphic can take a few seconds to download, but only the first time it is viewed; after that it is cached by your Web browser into memory.
3. Server Side Includes. SSIs allow you to generate portions of each page from a single template. When you change the template for the side menu, it reflects those changes on the pages which access that template file. But many ISPs don't permit SSIs, and they can slow down your site a bit.
4. Dynamic Page Generation. Larger sites tend to employ software that dynamically creates each Web page from a database -- sometimes every time it is viewed -- so changing the left side menu is easy. However, dynamically generated pages might not be indexed by the Web search engines, preventing search engine shoppers from learning about your internal pages. Research this carefully before you purchase.
