Chapter 3: Web Presentation Patterns

Overview

“An architect’s first work is apt to be spare and clean. He knows he doesn’t know what he is doing, so he does it carefully and with great restraint. As he designs the first work, frill after frill and embellishment after embellishment occur to him. These get stored away to be used ‘next time’…This second system is the most dangerous system a man ever designs…The general tendency is to over-design the second system using all the ideas and frills that were cautiously sidetracked on the first one.” — Frederick P. Brooks, Jr. in The Mythical Man Month, 1972^[1]

The first systems on the Web were simply linked static HTML pages that enabled document sharing between distributed teams. As user adoption increased, dynamic Web pages that responded to user input became common. Early dynamic pages were typically written as Common Gateway Interface (CGI) scripts. These CGI scripts not only contained the business logic for deciding what to display in response to user input, they also generated the presentation HTML. As demand for more complex logic increased, so did the demand for richer and more engaging presentations. This increased complexity strained the CGI programming model.

Soon page-based development (for example, ASP and JSP) emerged. This allowed developers to embed script directly into HTML pages, thus simplifying the programming model. As these embedded script applications became more complex, developers wanted to separate out business logic from presentation logic at the page level. In response, tag libraries with helper objects and code-behind page strategies emerged. Elaborate frameworks appeared, which offered dynamically configurable site navigation and command dispatchers, all at the cost of additional complexity. Given the wide range of Web presentation options now available, how do you choose the appropriate Web presentation design strategy for your application?

^[1]This quotation is intended to emphasize the dangers of adding unnecessary complexity to a system. By using Brooks’ original words, the authors of this guide are not advocating his particular choice of pronouns.