Web Database Applications with PHP and MySQL, 2nd Edition

Common Components

This section describes the components of the winestore that are used by all parts of the application. We discuss our extensions of the PEAR ITX templates that provide a framework for all winestore pages and special-purpose tools for building form pages. We also discuss our validation functions, database parameters, custom error handler, and general-purpose constants and functions. The authentication module is discussed in Chapter 20.

Application Templates

The winestore application uses the PEAR ITX template class discussed in Chapter 7 to abstract presentation from code structure. Templates make the code easier to modify and the HTML presentation easy to change. For example, if you want to change the look and feel of the application, you only need to edit the template files in the templates directory.

We don't use the ITX templates directly. Instead, because we populate the same placeholders with similar data in each script, we've extended them to create two new child classes with the reusable features we need. This saves coding in script files, and leads to a simpler application that's easy to adapt. These two new classes are stored in the includes/template.inc file discussed later.

The first class we've created is the winestoreTemplate class that has a basic skeleton structure used throughout the winestore. It's associated with the generic template templates/winestore.tpl that's shown later in Example 16-1 and uses the template to show error messages to the user, ...