6 Chapter 1. WAF Overview
1.2.3. Infrastructure
Infrastructure contains software to support the mechanics of application building at each layer of
the architecture (for example, serving page requests, styling the user interface, logging, specifying
metadata, storing data, etc.).
Note
This infrastructure exists independently from any specific problem domain and generally does not
depend on other WAF systems.
1.2.4. Persistence
Persistence handles the storage and retrieval of all information in WAF applications via Data Ob-
jects. Data Objects are implemented as a Java class library that supports CRUD (create, read, update,
and delete) operations for any type of Data Object. This is done through a set of generic interfaces:
DataObject,DataCollection,andDataAssociation.Persistence is discussedin detail inChap-
ter 2 WAF Component: Persistence.
1.2.5. Presentation
Presentation is responsible for presenting data in a structured format to the end user. WAF provides
three basic systems for presentation: Bebop, a web user interface component framework modeled
after Java Swing; Java Server Pages (JSP); and eXtensible Stylesheet Language (XSL). Presentation
is discussed in detail in Chapter 5 WAF Component: Presentation.
1.2.6. Web
The Web component ofWAF makes the persistent data and domain logic ofyour application available
to othersover protocols suchas HTTP. Itintegrates the JavaServlet API andthe kernel and persistence
components of WAF. For more information, see Chapter 6 WAF Component: Web.
1.3. Applications
Each WAF application adds code and other assets (stylesheets and PDL files) to each layer of the
architecture. The result is a complete application:
