This documentation is a reference guide to the Web transactions implementation model for developing IACs.

Web transactions are Internet-enabled R/3 dialog transactions that Internet and intranet users can call from a Web browser as Internet Application Components (IACs).

The Web transactions implementation model allows ABAP developers to use ABAP dialog programs as a basis for developing IACs.

The link between the Web server and the R/3 System is provided by the Internet Transaction Server (ITS), which acts as a generic Common Gateway Interface (CGI) program.

If you set up Web pages containing URLs, which link to the R/3 System, and a Web user makes a request by selecting one of these links, the request is processed as follows.

1. User starts a transaction in the Web browser.
2. The Web browser passes the request to the Web server.
3. The Web server forwards the request to the ITS.
4. The ITS establishes a connection with the R/3 System using the DIAG protocol, prepares the request, and starts the relevant transaction.

Since the ITS functions as a normal SAP GUI when communicating with R/3, it uses the DIAG protocol as the transmission channel for data exchange.

5. R/3 sends screen output to the ITS, which converts the data to HTML format, and returns it via the Web server to the Web browser, where it is displayed as an HTML page.

To implement a Web transaction, you must:

• Create a transaction in R/3
• Enable the R/3 transaction for Internet use

To do this, you must create the necessary external files required by the ITS to drive the transaction. These files make up an ITS service and consist of:

• An ITS service description
• A set of HTML templates (one for each R/3 screen)
• Language resource files (optional)
• Multipurpose Internet Mail Extension (MIME) files (optional)

To create these components, you use the SAP@Web Studio.

When generating the HTML templates that correspond to Web transaction screens, the ITS inserts additional HTML^Business statements into the standard HTML code.
HTML^Business is an SAP-specific macro language for handling data transfer between R/3 screens and HTML pages. At runtime, the ITS executes these extra statements to create the finished HTML pages to run the Web transaction.

Web transactions must satisfy special requirements regarding:

• Screen design

Since HTML (on the Internet side) and ABAP (on the R/3 side) offer different programming features, some objects used in ABAP programs or on R/3 screens are not supported by HTML, so you have to adapt the HTML code accordingly.

• User authorizations
• Use of BAPIs (Business Application Programming Interfaces) when applying precisely defined methods to business objects.

Apart from exchanging data between the Internet and the R/3 System, and converting HTML to R/3 screen data and vice versa, the ITS also performs system administration functions.

To support the development of Web transactions, there is a set of macros and functions that you can use to import data from, and export data to, the ITS. For further information, see:

For further information about creating, managing, and publishing the files required by the ITS to drive Web transactions, see:

For further information about HTML^Business, see:

For information about other implementation models for developing IACs, see: