All applications developed in the SAP@Web Studio are known to the Internet Transaction Server (ITS) as services.

A service is the set of files required by the ITS to drive an application that accesses data in the R/3 System and users can run from any Web browser. Each service can contain up to five ITS file types:

• A service file
• HTML templates
• Flow files
• Language resource files
• Multipurpose Internet Mail Extension (MIME) files

The ITS also derives information from the global service file, which contains settings that apply to all services.

The service file contains the service description, which is the set of parameters that determines how a service runs. If this information is incomplete at runtime, the ITS may derive some details from the global service file (see below) and/or require the user to enter logon information. There is one service file for each application.

Each service can be divided into one or more themes. Themes are instances of services that differ only in look and feel (appearance, graphics, layout or language). Each theme has its own set of files, which can include HTML templates, flow files, JavaScript files, language resource files and MIME files, but the functionality of the service is identical.

HTML templates are the means used by the ITS to display application screens in a Web browser when running a service. For each screen, there must be one HTML template. Each template contains standard HTML code and HTML^Business statements. HTML ^Business is an SAP-specific macro language, which allows you to merge R/3 data dynamically into HTML templates.

Flow files contain the flow logic that defines the dialog flow in screen-independent applications based on the ITS Flow Logic implementation model. The course of the dialog flow depends on what the user decides to do at runtime.

In these applications, there is one flow file for each HTML template that requires a dialog flow definition. Each flow file contains eXtensible Markup Language (XML) statements, using a predefined subset of XML elements.

Language resource files contain language-independent texts used by the ITS to run a service in a particular language.

Instead of hard-coded texts in a specific language, HTML templates contain placeholders and the actual texts are stored in language resource files. At runtime, the ITS looks for placeholders in the templates and replaces them with texts from the language resource file for the relevant language.

MIME files contain the image, sound, and video elements often included in services to enhance the visual appearance and effectiveness of applications.

Services also derive information from the global service file, which is created automatically during ITS setup and defines default parameter values for all services. The values defined in individual service files always override values in the global service file.

The following table summarizes the file types used in ITS-driven Internet applications and specifies their name format and extenson. The table also specifies whether each file type is required or optional.