Scenario 3. Distributed Processing

Some applications fall into the category called collaborative. These applications provide a single end-user interface, but their processing is performed at two or more different physical locations.

An EHLLAPI application can interact with host system applications by intercepting the communication between the host system and the terminal user. The host system presentation space is the vehicle used to intercept this data. The local application can request to be notified each time the presentation space is updated or whenever an AID key is pressed by the operator.

This workstation application can then cooperate with a host system application in any of the following ways:
  • On a field or presentation space basis using either the copy functions that address fields (Copy String to Field (33) function or Copy Field to String (34) function) or the functions that let you copy from and into presentation spaces (for example, Copy String to Presentation Space (15) function or Copy Presentation Space to String (8) function).
  • On a keystroke basis, using the Send Key (3) function.
  • On a file basis, for large blocks of data. You can have your application use the EHLLAPI file transfer capability (using Send File (90) function or Receive File (91) function) to transfer data or functions (such as load modules) and have it processed locally or remotely.