Part 3. Building the web interface

The web interface itself is the challenge that is unique to web programming. Most complete programs have a user interface, but other types of user interfaces—such as command-line interfaces and rich-client graphical user interfaces—involve other kinds of issues and different species of complexity.

One unique issue is the separation of HTML markup and program code. Another is the handling of the HTTP request. Among PHP developers, the standard solution to the first problem is web templates, and the object-oriented solution to the second one is the Model-View-Controller (MVC) pattern. In this part of the book, we will put both of these under close scrutiny. We will also look at ways to construct complex web pages out of independent components and how to handle input validation and forms.