High-Level Screen Management Intrinsic Library Reference Manual (32424-90002)

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instructions specified in the application. The instructions cover such
things as the initialization of field displays, key label display, and
the display of application messages in the message window.
The HPDREAD intrinsic reads and collects the information that the
operator supplies on the form. If any errors are detected, the HPDPROMPT
intrinsic is called to alert the operator to the error by highlighting
particular fields and/or displaying messages.
The supporting intrinsics enable the core intrinsics to transfer data by
performing the basic housekeeping tasks of enabling the terminal and
opening the forms file, and then disabling the terminal and closing the
forms file when the application is finished.
Figure 2-2. The Hi-Li Model
Hi-Li and the Application-ready Buffer (ARB)
A data buffer is passed by the application to HPDSEND, HPDREAD, and
HPDPRINTFORM. You can specify the instructions for how you want data
moved between this buffer and the form in one of two ways. In the first
way, you code your application to specify how you want the contents of
the data buffer handled by including a 'data description' parameter.
This is the direct method of transferring data, and Hi-Li supports five
such methods.