Dynamic Sites Take Over

An informal survey of Web developers (well, very informal - I called a couple of buddies on the phone) reveals that for medium-to-large corporate clients, dynamic sites, as opposed to flat sites, are now the rule. A "flat" site is one built out of static HTML pages. You code each page individually in HTML, put the pages upon the Web server, and there they are. On a "dynamic" site, on the other hand, an individual page doesn't exist as a finished HTML document until it is requested. When a user requests a page, the system builds it from three sets of data:

1. HTML templates, which define the overall layout of the page, and contain any elements that are common to all pages.
2. The content of the page, which is retrieved from a database.
3. Any user input which may be required to create the page.

Dynamic Web pages are nothing new, and many a flat site contains one or more dynamic sections. Such things as search engine results and discussion group posts are by definition dynamic, since they require user input. Also, there may be situations in which you want to rotate a certain part of a page's content, which can be done very easily (although inefficiently from a server-load standpoint) using server-side includes. I discussed this and other quick-n-dirty dynamic tricks in an URLier WDVL article.

Dynamic sections within a site may be handled with scripting, as is often the case with a search engine - there are lots of search engine scripts out there, ranging from cheap shareware to brand-name commercial solutions. More complex dynamic applications, such as an interactive discussion forum, are typically done by means of a software package that runs on the server. Here at Internet.com, we use a package called Web Crossings to power our discussion forums.

What about making a whole Web site dynamic? Very large Web sites have used the dynamic approach for a long time, but nowadays, even for medium-size sites, dynamic delivery is becoming the norm. There are many ways to build a dynamic site, ranging from homegrown systems using Perl, PHP, Java, VB, COBOL (well, maybe) or the language of your choice, to more structured commercial packages such as ColdFusion and ASP.

The advantages of a dynamic site are:

• It's easier to update and change content. If you need to change a page header, all you have to do is change one file, instead of doing a search-and-replace on all the pages affected, then uploading all those pages to the Web server.

• Since content is stored in a database as plain text (or graphics, audio or whatever), the people who create and maintain the content don't need to know anything about HTML, or about how the pages are organized and laid out. The tedious task of coding content into HTML templates is eliminated.

• Adding user interactivity is much easier. Today's Web users expect a high degree of interactivity. A dynamic system allows you to offer interactive features smoothly and efficiently, and to incorporate personalization features that wouldn't be possible with a flat site.

• Patchy and inefficient dynamic doodads can be eliminated. For example, if one had a fully dynamic site, the bandwidth-hogging SSIs mentioned above wouldn't be necessary. The dynamic system could do the same thing more efficiently.

• Compatibility problems can be dealt with more efficiently. For example, say you have a script that determines a user's browser version, and chooses a version of a page accordingly. Users with the latest browsers are shown a way-cool page with lots of Java and streaming media, while past-dwelling Luddites are shown a page of plain HTML. With a flat site, this would require creating (and storing on your Web server) two complete versions of every page. With a dynamic site, you'd only need to have different page templates. The content, stored in a database as plain text, would be the same for either version.

The full significance of this last item becomes apparent when you start thinking about accessing the Web from non-PC devices (I mean devices other than computers, not devices that aren't politically correct), which will soon be very common. If we had a flat site, which we wanted to be viewable on a Dick Tracy watch with a tiny video screen, we'd just about have to create a whole duplicate site, formatted appropriately. Ah, but had we that blessed entity, the Dynamic Site, then we'd only have to create a template that would format our content for that silly Dick Tracy watch. And when someone came out with a Star Trek communicator, which of course would require totally different formatting than the Dick Tracy watch, then would we truly begin to see how wise we were to choose the dynamic way.

Now that we've heard the cheerleading squad, how about the nay-sayers? Are there any disadvantages to dynamic sites? Oh, yes.

• Dynamic sites can be more crash-prone than flat sites. With a flat site, the only piece of software gadgetry on your end is the Web server itself, and all the popular Web servers are fairly bulletproof. With a dynamic site, you're adding a lot of complex scripting to the equation (plus the database). I'm sure to get a flood of protests about this statement, but speaking solely from my experience as a frequent Web surfer, I can tell you that dynamic sites tend to malfunction. A lot. A custom-scripted dynamic site can be quite reliable, if it is carefully designed and maintained, but that's a rarity in today's rush-and-release business world. The major off-the-shelf dynamic solutions have poor reputations when it comes to reliability. Active Server Pages (ASP) is made by Microsoft, which (to put it as delicately as I can) is not exactly world-famous for bulletproof products. The other big name, ColdFusion, has earned some harsh criticisms for its reliability. Of course, both products are being improved all the time, and their dependability, or lack thereof, is no different than any other type of complex software. A slightly higher error rate is the price you pay for the advantages of a dynamic site.

• A second drawback of dynamic sites is that they cost more to build and maintain. A flat site can be built without spending a penny on software, as a recent series of WDVL articles explains in detail. Neither ASP nor ColdFusion is free, although PHP and other do-it-yourself scripting solutions are. Naturally, dynamic sites require expertise to build and maintain. Folks who can write decent HTML are common, but people who know how to "do it dynamically" are rarer, and much more expensive.

• There's also the "open versus proprietary" question. HTML is an open, commonly-known standard that belongs to no one. Going the dynamic route locks you into doing things in a certain proprietary way, whether you use one of the commercial solutions or devise your own scripting system.

The drawbacks of dynamic systems are simply part of the deal, and shouldn't discourage Web developers from getting with the program. Cutting-edge technologies are always unreliable and expensive, but improvements are being made all the time. For an overview of the huge variety of Web authoring possibilities, check out the WDVL's Authoring section.

A Look at the Web Development World Ahead
A Look at the Web Development World Ahead
Interactivity is the name of the game