The Run-Time Architecture

This illustration shows the run-time architecture of a Web Designer application:

The top right corner of the picture shows the USoft repositories, where all application specifications are stored. These specifications fall into conceptual (CON) and external (ESI) definitions. The conceptual definitions describe the application logic and are made available in an encrypted <application name>.CON flat file. This happens at development time and is shown as a dotted arrow between the USoft CON repository and the CON flat file.

The external definitions describe the look-and-feel and the representation of the data for the generated web pages with their forms. These definitions are made available to the USoft Page Engine in a USoft-proprietary XML format. This happens when you publish the application, and is shown as a dotted arrow between the USoft ESI repository and the GUI XML file.

The numbers in the picture correspond with the following processes:

1.	At run time, Internet client browsers access the generated web pages embedded in a larger web site. The client browser sends an application data request to the web server. For example, when a client browser shows an info page, and changes a record.

2.	The server script pages (ASP or JSP) call the USoft Page Engine.

The USoft Page Engine analyses the browser requests, generates the necessary SQL statements, and sends these statements to the Rules Engine. The Rules Service handles all data manipulation requests from the generated web pages. The Rules Service uses one of its free Rules Engines for each request. The Rules Engines then control data access and apply all business rules.

4.	If the client computer asks for application data, the Rules Service generates an XML document on the fly, with the application data in it. This is shown in the picture as Data XML.

5.	The USoft Page Engine combines the GUI XML page definitions with the XML application data on the fly, in the Combined.xml file.

6.	The USoft Page Engine passes the Combined XML document together with the XSL transformation sheets to the XSL parser.

7.	The XSL parser merges the XML document with the transformation rules that are defined in the XSL files. The XSL processor then returns HTML files back to the USoft Page Engine.

8.	The USoft Page Engine then passes the HTML back to the web server.

9.	The HTML pages with CSS files on the left-hand side are the final deliverables distributed to client computers by a web server.