Component parts of Internet applications
By Mario Perez, Alexander Hildenbrand, Bernd Matzke, Peter Zencke
This excerpt comes from SAP R/3 on the Internet, published by Addison-Wesley. Click here to buy the book to read the full section.
While creating an Internet application, a developer encounters various tools and other diverse objects. The tools include executable programs and control files. The objects include various logical objects. Each developer must operate or generate some of these tools and elements.
ITS
ITS, (Internet Transaction Server), is the actual coupling between the Web server and the Internet on one side and the R/3 System on the other side. Developers have no direct access to this program
Virtual ITS
Several instances of the ITS can run on one server. A virtual ITS is simply one of the instances of the program.
ITS Debugger
The ITS Debugger is a special function of the ITS. It permits the Web application to switch to a normal SAPGUI in parallel so that the application becomes visible on the Web and the SAPGUI simultaneously.
SAP@Web-Studio
SAP@Web-Studio helps generate and process files stored in the file system of an NT computer that runs the ITS It also places any modified files back into storage in the R/3 System after processing
Service
The term service identifies an Internet application. A service name describes applications outside of the R/3 system, and can consist of up to 14 characters.
Theme
Specification of a theme can reference on of several design versions of a service. The differences remain purely visual.
Global service description
To log into the R/3 System, the ITS requires a great deal of information, including the name of the SAP System, login data and so on. The global service description stores tehse types of data that do not otherwise belong to a special service.
Individual service description
You must create a service description for each R/3 application that will run over the Web. This file contains parameters required by the ITS to call an R/3 transaction.
Application templates
Templates define HTML pages that contan supplemental information on the R/3 data that you wish to merge into a document. They also specify where the merge occurs. Every template corresponds to a screen of an R/3 application.
System templates
System templates can be generated and addressed as language-dependent templates, but cannot be subdivided into themes. Customers may not change system templates.
HTMLBusiness
SAP terminology uses HTML Business to refer to metastatements.
Language resources
You can process language resources in a file system outside of the R/3 System, preferably with SAP@Web-Studio. This method becomes mandatory during development.
Binary objects
Web applications also include graphics, sound files and additional objects. The Web server, rather than the ITS, inserts these objects into the HTML pages.
RFC channel
R/3 applications can use an RFC channel, much as the R/3 System uses the DIAG channel to transmit screen data. The application server and the front end use the RFC channel to exchange data bidirectionally.
Web RFC
A second RFC option also exists in addition to the mass data connection between the R/3 System and the SAPGUI interface. This option permits external applications to call special function modules of the R/3 System.
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