System Architect XT pages run on the server, which monitors and tracks the session state of each user. Maintaining session information allows System Architect XT to control which page elements to display, according to a user’s state in the current session. Some components are kept hidden until a certain condition is met; notice that the default login page does not display the Search for SA Items field, among others. That is because until a user meets the condition of being logged in, that user is not allowed to search the encyclopedia repository.

The basic building blocks for System Architect XT pages are components. There are different components types, each with predefined properties that you can copy, alter, relocate, reuse, or even remove. Some components, such as those displayed on page headers and footers are global and persist across all pages; others are only shown within certain pages.

Components are created with the <component></component> tags, and have multiple properties (name, type, class, position, style, size, and so on) that determine their appearance, placement, and content on a page. A System Architect XT page that is rendered to the user as a single page is actually an assembly of various components (some of which contain other pages) that are plugged into the System Architect XT web page, as defined by the XML Configuration File. Within the component tags, you can insert text, links, buttons, other pages, and other elements that you see throughout System Architect XT pages. For example, the title and the text that appears on the Home page is held within a component named Intro.

The image below shows the structure of the Page Configuration file commercial.xml (defence.xml has same structure). It illustrates the nesting of components within components. The header component is expanded in this view (using Microsoft XML Notepad 2006).