Online Program Process Chain

The diagram below shows the relationship between the user interface (Lawson Interface Desktop or Lawson Portal) and online application programs.

Illustration: Online program process chain
Component Description
User Interface The user interface (Lawson Portal or Lawson Interface Desktop (LID) connects to the application programs. In the case of the Lawson Portal, it goes first through the Internet Object Services (IOS). LID resides on a PC and uses lapm to request information from the application programs.
UNIVSRV UNIVSRV is a job running on the server under the subsystem, and is used to make the initial call to lapm for LID.
lapm The Lawson Presentation Manager, lapm resides on the server and controls the conversation between the user interface (LID) and the application programs and database.
Application Programs The Lawson programs reside on the server and contain the processing logic for the applications.
Database Driver The Lawson "C" driver program used to handle data retrieval and updating for the application programs.
IBM i Database The database library in which the data resides.

The following steps occur during the online program process chain:

  1. Through the user interface, the user begins a Lawson session. If the user interface is LID, LID contacts the UNIVSRV job on IBM i. If the user interface is Lawson Portal, Lawson Portal accesses the Internet Object Services programs.

  2. UNIVSRV spawns an lapm job and connects LID to lapm.

  3. When the user requests a form, the user interface displays the form and the user then requests information (for example, selects the Next form action to get the next record).

  4. Depending on the user interface, either the lapm program or the IOS programs interpret the request. In the case of online transactions, such as Adds or Inquiries, the request is sent to latm, which in turns starts the appropriate application program. In the case of Selects and Drill Arounds, the data is retrieved via the database driver, without going through latm or application programs.

  5. In the case of online transactions, the application program, using its database procedures, sends the request to the database driver. The database driver retrieves the data from the database and sends it back to the application program.

  6. The application program sends the data back to lapm or the IOS.

  7. The lapm program or IOS returns the results to the user interface